2018年4月1日 · cos^2pi=1 cos^2pi=(cospi)^2=(-1)^2=1. ... What is the value of cos^2 pi? Trigonometry. 1 Answer Monzur R. ...

2015年10月2日 · You get cos(2pi)=1 The easiest way (at least for me) it is "to see" its value using the unit circle and the meaning of cos in terms of the "length"of it. Consider a circle of radius 1 and on this circle a point P. The point produces a projection, depending upon the angle alpha, on the horizontal axis that is our cos (segment OA):

Using the double angle formula, how do you find the function values for #cos^2(pi/12) and sin^2(pi/8)#? How do you find the exact value of the expression sin 2x, cos 2x, and tan 2x given #Sin x = 12/13# where x lies on Quadrant I?

2018年3月15日 · We know that ,cos is an even function. #=>cos(-theta)=costheta# #:.cos(x-pi/2)=cos(pi/2-x)=sinx# OR #cos(A-B)=cosAcosB+sinAsinB#

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2016年9月30日 · Use the known trigonometric identity . #cos(a+b)=cosa*cosb-sina*sinb# we have that. #cos(x+pi/2)=cosx*cos(pi/2)-sinx*sin(pi/2)=cosx*0-sinx*1=-sinx#

2016年4月18日 · How do you find all the solutions for #2 \sin^2 \frac{x}{4}-3 \cos \frac{x}{4} = 0# over the

2016年3月31日 · Since this is a proof, we do not have a short answer. See the explanation below.

2016年8月4日 · As cos(-\pi/2)=0, 4cos^2(-pi/2)=4(0^2)=0. Remember that any multiple of \pi plus or minus \pi/2 gives a cosine equal to zero.

2016年4月7日 · sqrt2/2 Apply the trig identity: cos 2a = cos^2 a - sin^2 a cos^2 (pi/8) - sin^2 (pi/8) = cos (pi/4) Trig table --> cos (pi/4) = sqrt2/2