In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions [1] [2]) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths.Jul 31, 2019 · 1) In the unit circle the x represent the cosine of the function and the y represent the sine of the trigonometric function. 2) Looking at the unit circle I noticed that cos (x) =1, corresponds to 360°. in other words cos (360º) =1, the answer is x=360º or x=2π radians. 3) you can check your answer in your graphing calculator by pressing ... Mar 16, 2020 · how to plot cosx*coshx+1=0. Learn more about cosxcosh+1=0, plot clc clear close all syms x f(x) = (cos(x))*(cosh(x))+1; fplot(x,f) xlim([0 10]); ylim([-100 100]); Why is the gragh cut off?? In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions [1] [2]) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths. cos^2 x + sin^2 x = 1. sin x/cos x = tan x. You want to simplify an equation down so you can use one of the trig identities to simplify your answer even more. some other identities (you will learn later) include -. cos x/sin x = cot x. 1 + tan^2 x = sec^2 x. 1 + cot^2 x = csc^2 x. hope this helped! From Pythagoras theorem we get: sin2x +cos2x = 1. So: sin2x = 1 − cos2x = (1 − cosx)(1 + cosx) Answer link.What is tan 30 using the unit circle? tan 30° = 1/√3. To find this answer on the unit circle, we start by finding the sin and cos values as the y-coordinate and x-coordinate, respectively: sin 30° = 1/2 and cos 30° = √3/2. Now use the formula. Recall that tan 30° = sin 30° / cos 30° = (1/2) / (√3/2) = 1/√3, as claimed.Explanation: In the trigonometric circle you will notice that cos (x)=0 corresponds to x = π 2 and also x = − π 2. Additionally to these all the angles that make a complete turn of the circle ( 2kπ) plus ± π 2 correspond to cos (x)=0. So you have: x = ± π 2 +2kπ,k ∈ Z. If you try to see which are the first elements (from k =0, 1,2 ...Graph y=cos(x)-1. Step 1. Use the form to find the variables used to find the amplitude, period, phase shift, and vertical shift. Step 2. Find the amplitude . Amplitude:A Taylor Series is an expansion of some function into an infinite sum of terms, where each term has a larger exponent like x, x 2, x 3, etc. Example: The Taylor Series for e x e x = 1 + x + x 2 2! + x 3 3! + x 4 4! + x 5 5! + ... The inverse of sine is denoted as arccos or cos-1 x. For a right triangle with sides 1, 2, and √3, the cos function can be used to measure the angle. In this, the cos of angle A will be, cos(a)= adjacent/hypotenuse.1+cosx. Natural Language; Math Input; Extended Keyboard Examples Upload Random. Compute answers using Wolfram's breakthrough technology & knowledgebase, relied on by ... The Cosine function ( cos (x) ) The cosine is a trigonometric function of an angle, usually defined for acute angles within a right-angled triangle as the ratio of the length of the adjacent side to the hypotenuse. It is the complement to the sine. In the illustration below, cos (α) = b/c and cos (β) = a/c. Solve for x cos (x)=1. cos (x) = 1 cos ( x) = 1. Take the inverse cosine of both sides of the equation to extract x x from inside the cosine. x = arccos(1) x = arccos ( 1) Simplify the right side. Tap for more steps... x = 0 x = 0. The cosine function is positive in the first and fourth quadrants. To find the second solution, subtract the ... Arccos. Arccosine, written as arccos or cos -1 (not to be confused with ), is the inverse cosine function. Both arccos and cos -1 are the same thing. Cosine only has an inverse on a restricted domain, 0 ≤ x ≤ π. In the figure below, the portion of the graph highlighted in red shows the portion of the graph of cos (x) that has an inverse.Write each expression with a common denominator of (1+cos(x))(1− cos(x)) ( 1 + cos ( x)) ( 1 - cos ( x)), by multiplying each by an appropriate factor of 1 1. Tap for more steps... Combine the numerators over the common denominator. Simplify the numerator. (cotx)2 +1 = (cosecx)2 Odd and even properties cos( x) = cos(x) sin( x) = sin(x) tan( x) = tan(x) Double angle formulas sin(2x) = 2sinxcosx cos(2x) = (cosx)2 (sinx)2 cos(2x) = 2(cosx)2 1 cos(2x) = 1 2(sinx)2 Half angle formulas sin(1 2 x) 2 = 1 2 (1 cosx) cos(1 2 x) 2 = 1 2 (1+cosx) Sums and di erences of angles cos(A+B) = cosAcosB sinAsinB cos ...2cos(x)sin(x) Which we can say it's a sum. cos(x)sin(x) + sin(x)cos(x) Which is the double angle formula of the sine. cos(x)sin(x) + sin(x)cos(x) = sin(2x) But since we multiplied by 2 early on to get to that, we need to divide by two to make the equality, so. cos(x)sin(x) = sin(2x) 2. Answer link.Free trigonometric equation calculator - solve trigonometric equations step-by-stepsin2x +cos2x = 1. where we can subtract cos2x from both sides to get what we have in blue above: sin2x = 1 − cos2x. Thus, this expression is equal to. sin2x. All we did was use the difference of squares property to our advantage, recognize that the expression we had is derived from the Pythagorean Identity, use it, and simplify. Hope this helps!Graph y=cos(x)-1. Step 1. Use the form to find the variables used to find the amplitude, period, phase shift, and vertical shift. Step 2. Find the amplitude . Amplitude:The inverse of sine is denoted as arccos or cos-1 x. For a right triangle with sides 1, 2, and √3, the cos function can be used to measure the angle. In this, the cos of angle A will be, cos(a)= adjacent/hypotenuse. Solution. Determine the formula of 1 - cos x sin x. It is known that 1 - c o s ( 2 θ) = 2 s i n 2 θ and s i n ( 2 θ) = 2 s i n θ c o s θ. So, 1 - cos x = 2 sin 2 x 2 and sin x = 2 sin x 2 cos x 2. Substitute the values into the expression 1 - cos x sin x and simplify: Hence, the formula for 1 - cos x sin x is tan x 2.Mathematically, it is written as cos-1 (x) and is the inverse function of the trigonometric function cosine, cos(x). An important thing to note is that inverse cosine is not the reciprocal of cos x. There are 6 inverse trigonometric functions as sin-1 x, cos-1 x, tan-1 x, csc-1 x, sec-1 x, cot-1 x. Hero and Nghi, I think I could invoke more interest by including the. solutions for cosx − sinx = 1, and for that matter, secx ± tanx = 1, that become. cosx − sinx = 1 and cosx +sinx = 1, upon multiplication by. cos x, when x ≠ an odd multiple of π 2. For cos x - sin x = 1, the general solution is. x = 2nπ and x = (4n − 1) π 2,n = 0 ...Free math problem solver answers your algebra, geometry, trigonometry, calculus, and statistics homework questions with step-by-step explanations, just like a math tutor. May 29, 2023 · Misc 16 Find the derivative of the following functions (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers ... Sep 30, 2016 · Explanation: The function cos(x) has period 2π and cos(0) = 1. Hence: cos(2nπ) = 1 for any integer n. graph {cos (x) [-10, 10, -5, 5]} Answer link. The fixed point iteration x n+1 = cos(x n) with initial value x 0 = −1 converges to the Dottie number. Zero is the only real fixed point of the sine function; in other words the only intersection of the sine function and the identity function is sin ( 0 ) = 0 {\displaystyle \sin(0)=0} . clc clear close all syms x f(x) = (cos(x))*(cosh(x))+1; fplot(x,f) xlim([0 10]); ylim([-100 100]); Why is the gragh cut off??May 29, 2023 · Misc 16 Find the derivative of the following functions (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers ... Free Pre-Algebra, Algebra, Trigonometry, Calculus, Geometry, Statistics and Chemistry calculators step-by-stepPrecalculus. Simplify (1-cos (x))/ (cos (x)) Step 1. Nothing further can be done with this topic. Please check the expression entered or try another topic.First sketch 1-cos x then x. Determine where functions 1-cos x and x are positive and negative to determine where (1-cos x)/x will be positive and negative. Find any asymptotes (x=0). To help sketch determin whether the function is odd and even. If required check for concavity using the second derivative as well as max and minimumsMay 29, 2023 · Misc 16 Find the derivative of the following functions (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers ... 1. Hint The appearance of 1 + cos x 1 + cos x suggests we can produce an expression without a constant term in the denominator by substituting x = 2t x = 2 t and using the half-angle identity cos2 t = 12(1 + cos 2t) cos 2 t = 1 2 ( 1 + cos 2 t). Share.Precalculus. Simplify (1-cos (x))/ (cos (x)) Step 1. Nothing further can be done with this topic. Please check the expression entered or try another topic. Free trigonometric equation calculator - solve trigonometric equations step-by-stepAug 16, 2016 · False due to a clash of conventions. If n > 1 is a positive integer, then: cos^n x = (cos x)^n This is a convenience of notation, to avoid having to use parentheses to distinguish, for example: (cos x)^2 and cos (x^2) By convention we can write: cos^2 x and cos x^2 respectively, without ambiguity. However, in the case of -1, we have a clash of notation. If f(x) is a function, then f^(-1)(x) is ... Explanation: since cosx < 0 then x is in second/third quadrants. x = cos−1( 1 √2) = π 4 ← related acute angle. ⇒ x = π− π 4 = 3π 4 ← second quadrant. or x = π+ π 4 = 5π 4 ← third quadrant. due to the periodicity of the cosine the solutions will. repeat every 2π. solutions are. x = 3π 4 +2nπ → (n ∈ Z)Free math problem solver answers your algebra, geometry, trigonometry, calculus, and statistics homework questions with step-by-step explanations, just like a math tutor. In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions [1] [2]) are real functions which relate an angle of a right-angled triangle to ratios of two side lengths.First sketch 1-cos x then x. Determine where functions 1-cos x and x are positive and negative to determine where (1-cos x)/x will be positive and negative. Find any asymptotes (x=0). To help sketch determin whether the function is odd and even. If required check for concavity using the second derivative as well as max and minimums1-cos^{2}x. en. Related Symbolab blog posts. Practice, practice, practice. Math can be an intimidating subject. Each new topic we learn has symbols and problems we ... What is tan 30 using the unit circle? tan 30° = 1/√3. To find this answer on the unit circle, we start by finding the sin and cos values as the y-coordinate and x-coordinate, respectively: sin 30° = 1/2 and cos 30° = √3/2. Now use the formula. Recall that tan 30° = sin 30° / cos 30° = (1/2) / (√3/2) = 1/√3, as claimed.The Cosine function ( cos (x) ) The cosine is a trigonometric function of an angle, usually defined for acute angles within a right-angled triangle as the ratio of the length of the adjacent side to the hypotenuse. It is the complement to the sine. In the illustration below, cos (α) = b/c and cos (β) = a/c. May 29, 2023 · Ex 7.3, 8 1 − 𝑐𝑜𝑠 𝑥1 + 𝑐𝑜𝑠 𝑥 1 − cos𝑥1 + cos𝑥 We know that Thus, our equation becomes 1 − cos𝑥1 + cos𝑥 𝑑𝑥= 2 sin2 𝑥22 cos2 𝑥2 = sin2 𝑥2 cos2 𝑥2 𝑑𝑥 = tan2 ... Sine and Cosine Laws in Triangles. In any triangle we have: 1 - The sine law. sin A / a = sin B / b = sin C / c. 2 - The cosine laws. a 2 = b 2 + c 2 - 2 b c cos A. b 2 = a 2 + c 2 - 2 a c cos B. c 2 = a 2 + b 2 - 2 a b cos C.A Taylor Series is an expansion of some function into an infinite sum of terms, where each term has a larger exponent like x, x 2, x 3, etc. Example: The Taylor Series for e x e x = 1 + x + x 2 2! + x 3 3! + x 4 4! + x 5 5! + ... Misc 16 Find the derivative of the following functions (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers ...Mathematically, it is written as cos-1 (x) and is the inverse function of the trigonometric function cosine, cos(x). An important thing to note is that inverse cosine is not the reciprocal of cos x. There are 6 inverse trigonometric functions as sin-1 x, cos-1 x, tan-1 x, csc-1 x, sec-1 x, cot-1 x. Simplify cos(x)*cos(x) Step 1. Raise to the power of . Step 2. Raise to the power of . Step 3. Use the power rule to combine exponents. Step 4. Add and .It follows that. arccos(cos x) = arccos(cos(d(x))) = d(x) (x ∈ R) , arccos ( cos x) = arccos ( cos ( d ( x))) = d ( x) ( x ∈ R) , which reveals arccos ∘ cos arccos ∘ cos to be a sawtooth function. Share. edited Aug 29, 2018 at 1:58. user46234. answered Mar 10, 2018 at 17:31. Christian Blatter. Graph y=cos(x) Step 1. Use the form to find the variables used to find the amplitude, period, phase shift, and vertical shift. Step 2. Find the amplitude . Amplitude:Aug 16, 2016 · False due to a clash of conventions. If n > 1 is a positive integer, then: cos^n x = (cos x)^n This is a convenience of notation, to avoid having to use parentheses to distinguish, for example: (cos x)^2 and cos (x^2) By convention we can write: cos^2 x and cos x^2 respectively, without ambiguity. However, in the case of -1, we have a clash of notation. If f(x) is a function, then f^(-1)(x) is ... Solve for ? cos (x)=1/2. cos (x) = 1 2 cos ( x) = 1 2. Take the inverse cosine of both sides of the equation to extract x x from inside the cosine. x = arccos(1 2) x = arccos ( 1 2) Simplify the right side. Tap for more steps... x = π 3 x = π 3. The cosine function is positive in the first and fourth quadrants. Jun 24, 2016 · Hero and Nghi, I think I could invoke more interest by including the. solutions for cosx − sinx = 1, and for that matter, secx ± tanx = 1, that become. cosx − sinx = 1 and cosx +sinx = 1, upon multiplication by. cos x, when x ≠ an odd multiple of π 2. For cos x - sin x = 1, the general solution is. x = 2nπ and x = (4n − 1) π 2,n = 0 ... Solve for x cos (x)=-1. cos (x) = −1 cos ( x) = - 1. Take the inverse cosine of both sides of the equation to extract x x from inside the cosine. x = arccos(−1) x = arccos ( - 1) Simplify the right side. Tap for more steps... x = π x = π. The cosine function is negative in the second and third quadrants. To find the second solution ... Introduction to Trigonometric Identities and Equations; 7.1 Solving Trigonometric Equations with Identities; 7.2 Sum and Difference Identities; 7.3 Double-Angle, Half-Angle, and Reduction FormulasWrite each expression with a common denominator of (1−cos(x))(1+ cos(x)) ( 1 - cos ( x)) ( 1 + cos ( x)), by multiplying each by an appropriate factor of 1 1. Tap for more steps... Combine the numerators over the common denominator. Simplify the numerator.Solution. Determine the formula of 1 - cos x sin x. It is known that 1 - c o s ( 2 θ) = 2 s i n 2 θ and s i n ( 2 θ) = 2 s i n θ c o s θ. So, 1 - cos x = 2 sin 2 x 2 and sin x = 2 sin x 2 cos x 2. Substitute the values into the expression 1 - cos x sin x and simplify: Hence, the formula for 1 - cos x sin x is tan x 2. The fixed point iteration x n+1 = cos(x n) with initial value x 0 = −1 converges to the Dottie number. Zero is the only real fixed point of the sine function; in other words the only intersection of the sine function and the identity function is sin ( 0 ) = 0 {\displaystyle \sin(0)=0} . Graph y=cos(x-1) Step 1. Use the form to find the variables used to find the amplitude, period, phase shift, ... Step 6.5.1. Replace the variable with in the expression. (cotx)2 +1 = (cosecx)2 Odd and even properties cos( x) = cos(x) sin( x) = sin(x) tan( x) = tan(x) Double angle formulas sin(2x) = 2sinxcosx cos(2x) = (cosx)2 (sinx)2 cos(2x) = 2(cosx)2 1 cos(2x) = 1 2(sinx)2 Half angle formulas sin(1 2 x) 2 = 1 2 (1 cosx) cos(1 2 x) 2 = 1 2 (1+cosx) Sums and di erences of angles cos(A+B) = cosAcosB sinAsinB cos ... Free math problem solver answers your algebra, geometry, trigonometry, calculus, and statistics homework questions with step-by-step explanations, just like a math tutor. Use the form asec(bx−c)+ d a sec ( b x - c) + d to find the variables used to find the amplitude, period, phase shift, and vertical shift. a = 1 a = 1. b = 1 b = 1. c = 0 c = 0. d = 0 d = 0. Since the graph of the function sec s e c does not have a maximum or minimum value, there can be no value for the amplitude. Amplitude: None.So I've been trying to show that $ | \cos x - 1 | \leq | x | $ for all x values, usin... Stack Exchange Network Stack Exchange network consists of 183 Q&A communities including Stack Overflow , the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.Jun 18, 2016 · At this point, we've simplified to integral ∫ 1 cosx −1 dx to ∫ −cotxcscx −csc2xdx. Using the sum rule, this becomes: ∫ − cotxcscxdx + ∫ − csc2xdx. The first of these is cscx (because the derivative of cscx is −cotxcscx) and the second is cotx (because the derivative of cotx is −csc2x ). Add on the constant of integration ... lim_(x->0) (cos(x)-1)/x = 0. We determine this by utilising L'hospital's Rule. To paraphrase, L'Hospital's rule states that when given a limit of the form lim_(x→a)f(x)/g(x), where f(a) and g(a) are values that cause the limit to be indeterminate (most often, if both are 0, or some form of ∞), then as long as both functions are continuous and differentiable at and in the vicinity of a, one ...sec A = 1/cos A tan A = sin A/cos A sin^2 A + cos^2 A = 1 sec x + tan x = (1+sin x)/cos x = ((1+sin x)(1-sin x))/(cos x(1-sin x)) = (1-sin^2 x)/(cos x(1-sin x)) = cos ...Jun 26, 2016 · From Pythagoras theorem we get: sin2x +cos2x = 1. So: sin2x = 1 − cos2x = (1 − cosx)(1 + cosx) Answer link. Solve for x cos(x)(cos(x)-1)=0. Step 1. If any individual factor on the left side of the equation is equal to , the entire expression will be equal to . Step 2.E 1 (sin x, cos x, tan x) = E 2 (sin x, cos x, tan x) Where E 1 and E 2 are rational functions. Since sine, cosine and tangent are the major trigonometric functions, hence the solutions will be derived for the equations comprising these three ratios. However, the solutions for the other three ratios such as secant, cosecant and cotangent can be ...Compute answers using Wolfram's breakthrough technology & knowledgebase, relied on by millions of students & professionals. For math, science, nutrition, history ...Trigonometry. Solve for ? cos (x)=-1/2. cos (x) = − 1 2 cos ( x) = - 1 2. Take the inverse cosine of both sides of the equation to extract x x from inside the cosine. x = arccos(−1 2) x = arccos ( - 1 2) Simplify the right side. Tap for more steps... x = 2π 3 x = 2 π 3. The cosine function is negative in the second and third quadrants.1 Answer. Chandra S. Aug 14, 2015. cos x = - 1/2 = cos 2 π /3 ⇒ x = 2 π /3.Trigonometric Identities Resources · Cool Tools · Formulas & Tables · References · Test Preparation · Study Tips · Wonders of Math Search Trigonometric Identities ( Math | Trig | Identities) sin (-x) = -sin (x) csc (-x) = -csc (x) cos (-x) = cos (x) sec (-x) = sec (x) tan (-x) = -tan (x) cot (-x) = -cot (x)Sep 30, 2016 · Explanation: The function cos(x) has period 2π and cos(0) = 1. Hence: cos(2nπ) = 1 for any integer n. graph {cos (x) [-10, 10, -5, 5]} Answer link. May 29, 2023 · Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class. Book a free demo. Transcript. Show More. Next: Ex 7.3, 10 Important → Ask a doubt Trigonometry. Solve for ? cos (x)=-1/2. cos (x) = − 1 2 cos ( x) = - 1 2. Take the inverse cosine of both sides of the equation to extract x x from inside the cosine. x = arccos(−1 2) x = arccos ( - 1 2) Simplify the right side. Tap for more steps... x = 2π 3 x = 2 π 3. The cosine function is negative in the second and third quadrants.Precalculus. Simplify (1-cos (x))/ (cos (x)) Step 1. Nothing further can be done with this topic. Please check the expression entered or try another topic.
What is the formula of (1 - cos x) / sin x? Solution: As we know that (1 - cos x) = 2sin 2 (x/2) and sin x = 2sin (x/2).cos (x/2) (1 - cos x) = 2sin 2 (x/2) ---- (1 ... . Auto mataru
Found 2 solutions by josgarithmetic, Boreal: Answer by josgarithmetic (38702) ( Show Source ): You can put this solution on YOUR website! Answer by Boreal (15207) ( Show Source ): You can put this solution on YOUR website! cosx/ (1+sinx) cos x (1-sinx)/ [ (1+sinx) (1-sinx)] ;; multiply by (1-sin x/1-sin x) cosx-sinxcosx/ (1-sin^2x) ;;; 1-sin^2x ... lim_(x->0) (cos(x)-1)/x = 0. We determine this by utilising L'hospital's Rule. To paraphrase, L'Hospital's rule states that when given a limit of the form lim_(x→a)f(x)/g(x), where f(a) and g(a) are values that cause the limit to be indeterminate (most often, if both are 0, or some form of ∞), then as long as both functions are continuous and differentiable at and in the vicinity of a, one ...False due to a clash of conventions. If n > 1 is a positive integer, then: cos^n x = (cos x)^n This is a convenience of notation, to avoid having to use parentheses to distinguish, for example: (cos x)^2 and cos (x^2) By convention we can write: cos^2 x and cos x^2 respectively, without ambiguity. However, in the case of -1, we have a clash of notation. If f(x) is a function, then f^(-1)(x) is ...Jan 31, 2017 · 1. Hint The appearance of 1 + cos x 1 + cos x suggests we can produce an expression without a constant term in the denominator by substituting x = 2t x = 2 t and using the half-angle identity cos2 t = 12(1 + cos 2t) cos 2 t = 1 2 ( 1 + cos 2 t). Share. It follows that. arccos(cos x) = arccos(cos(d(x))) = d(x) (x ∈ R) , arccos ( cos x) = arccos ( cos ( d ( x))) = d ( x) ( x ∈ R) , which reveals arccos ∘ cos arccos ∘ cos to be a sawtooth function. Share. edited Aug 29, 2018 at 1:58. user46234. answered Mar 10, 2018 at 17:31. Christian Blatter.First sketch 1-cos x then x. Determine where functions 1-cos x and x are positive and negative to determine where (1-cos x)/x will be positive and negative. Find any asymptotes (x=0). To help sketch determin whether the function is odd and even. If required check for concavity using the second derivative as well as max and minimums1 Answer. Chandra S. Aug 14, 2015. cos x = - 1/2 = cos 2 π /3 ⇒ x = 2 π /3.May 27, 2017 · The first step is to multiply the two expressions between parentheses : (II) There is a trigonometric identity that states : Working with this expression : ⇒. (I) Using the equation (I) in (II) : ⇒. arrow right. The usual principal values of the arcsin(x) and arccos(x) functions graphed on the Cartesian plane. The inverse function of sine is arcsine (arcsin or asin) or inverse sine (sin −1). The inverse function of cosine is arccosine (arccos, acos, or cos −1). (The superscript of −1 in sin −1 and cos −1 denotes the inverse of a function, not ...My origin equation is 2 x^2 (-1 + Cos[x] Cosh[x]) == 0, how could I know I should first divide the equation by x^2, before applying your code on big x approximation.Solution. Determine the formula of 1 - cos x sin x. It is known that 1 - c o s ( 2 θ) = 2 s i n 2 θ and s i n ( 2 θ) = 2 s i n θ c o s θ. So, 1 - cos x = 2 sin 2 x 2 and sin x = 2 sin x 2 cos x 2. Substitute the values into the expression 1 - cos x sin x and simplify: Hence, the formula for 1 - cos x sin x is tan x 2. Trigonometry. Solve for ? cos (x)=-1/2. cos (x) = − 1 2 cos ( x) = - 1 2. Take the inverse cosine of both sides of the equation to extract x x from inside the cosine. x = arccos(−1 2) x = arccos ( - 1 2) Simplify the right side. Tap for more steps... x = 2π 3 x = 2 π 3. The cosine function is negative in the second and third quadrants.In y = cos(x), the center is the x-axis, and the amplitude is 1, or A=1, so the highest and lowest points the graph reaches are 1 and -1, the range of cos(x). Compared to y=cos(x), shown in purple below, the function y=2 cos(x) (red) has an amplitude that is twice that of the original cosine graph..