If sin t 38 7 and cos t 18 find the sine and cosine of the

If sin t = -3/8 7, and cos t = 1/8, find the sine and cosine of the given values. (a) t + pi sin(t + pi) = cos(t + pi) = (b) -t sin(-t) = cos(-t) = (c) t + pi/2 sin(t + pi/2) = cos(t + pi/2) = (d) -t + pi/2 sin(-t + pi/2) = cos(-t + pi/2) =

Solution

sint = - 3sqrt7/8 ; cost = 1/8

a) sin(t +pi)

As we know sin(180 +x) = -sinx

So, sin(t +pi) = -sint = 3sqrt7/8

b) sin(-t)

As sin(-x) = -sinx

So, sin(-t) = 3sqrt(7)/8

c) sin(t +pi/2) = cost

sin(t +pi/2) = cost = 1/8

d) sin( -t +pi/2)

as we know : sin (90 -x) = cosx

So, sin(pi/2 -t) = cost = 1/8