Find the value of `costheta+cos(pi+theta)+cos(2pi+theta)+...`to 20 terms.

If sec theta=4 , find the value of cos theta/(4cos^2 theta+3sin^2 theta) .

Find -the least value of sec^2theta+cos^2theta

lf 5 cos theta=7 sin theta , find the value of ( sin theta + cos theta)/(2 sin theta -3 cos theta) .

If 4 tan theta=3 , find the value of (4 sin theta-3 cos theta)/(4 sin theta+3 cos theta) .

Choose the correct option The value of sin theta cos (90- theta)+cos theta sin (90- theta) is

Find the value of cos^(-1)("cos"(9pi)/(8)) .

If tantheta=5/12 and and cos theta is negative, find the value of (sintheta+cos(-theta))/(sec(-theta)+tantheta)

Find cos^2 theta - sin^2 theta . .

Find the value of cos theta and tan theta if sin theta =-3/5 and piltthetalt3pi/2

The value of cos(40^@+theta)-sin(50^@-theta) is