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May 25, 2018 · To find the exact value of cos(180o) −sin(180o) −1 − 0 = −1. Answer link. -1 Within the unit circle, cosine provides the x coordinate of a point on the surface of the circle. Sine provides the y coordinate of a point on the surface of the circle. At 180^o, the point on the unit circle surface is (-1,0). So this means: x=cos (180^o) = -1 ...
Jan 4, 2017 · Learn how to find the exact value of cos 180 with a step-by-step explanation on Socratic.org.
Oct 30, 2015 · cos-120^@=-1/2=-0,5 cos(-120^@)=cos120^@ =cos(180^@-60^@) =-cos60^@ =-1/2. Note: Above I have used the 180^@ rule. Alternatively I could also have used the 90^@ rule, or the compound angle formulae for either sin or cos, or a number of other possible methods as well, and each would result in exactly the same final answer. Since the question did not explicitly specify which method to use, or how to express the final answer, any valid method will suffice.
May 20, 2016 · Answer link. pi=3.14159265... is a transcendental number. This is a limit problem of x to pi of cos x. cos x is continuous at x = pi. Both cos pi_+ and cos pi_ ( - ) approach to the same limit -1. The Calculator value of cos pi = cos 180^o = -1 is by truncation and rounding of (say) 10-sd -1.000000000 approximation obtained from an ...
Dec 25, 2016 · Dec 25, 2016. You can use a reduction formula. See explanation. Explanation: cos120=cos (180-60)=-cos60=-1/2. Answer link.
May 10, 2015 · Cos 135° is an angle in the second quadrant. In the second quadrant, cos is negative. cosθ = x r. cos135 = cos(180 − 45) = −cos45°. An angle of 45° is found in a right-angled triangle of sides 1:1:√2. cos45° = 1 √2. ∴ cos135° = −cos45° = − 1 √2. Note that √2 is an irrational number and cannot be given as an exact decimal.
Jun 24, 2016 · How do you find the exact value of #cos54#? Trigonometry Trigonometric Identities and Equations Half-Angle Identities. 1 Answer
Apr 26, 2018 · cos (a + b) = cos a.cos b - sin a. sin b In this case --> cos 225 = cos (180 + 45) = cos 180.cos 45 - sin 180.sin 45. Since: sin 180 = 0; cos 180 = -1, and #cos 45 = sqrt2/2#, therefor: #cos 225 = (-1)sqrt2/2 = - sqrt2/2# #sec 225 = 1/(cos 225) = - 2/(sqrt2) = - sqrt2# Check by calculator. cos 225 = - 0.707 --> sec 225 = 1/0.707 = 1.414
How do you find the trigonometric functions of any angle? Well, I guess you could use a special representation of the function through a sum of terms, also known as Taylor Series. It is, basically, what happens in your pocket calculator when you evaluate, for example, sin (30°). Your calculator does this: sin (theta)=theta-theta^3/ (3!)+theta ...
May 7, 2015 · What is the value of #sin -45^@#? How do you find the trigonometric functions of values that are greater than #360^@#? How do you use the reference angles to find #sin210cos330-tan 135#?
