Question

Establish the identity
5cos(theta)^2+3sin(theta)^2=3+2cos^2(theta)

Answer 1

5cos(theta)^2+3sin(theta)^2
=2cos(theta)^2+(3cos^2(theta)+3sin(theta)^2)
=2cos(theta)^2+3(cos^2(theta)+sin(theta)^2)
=2cos(theta)^2+3*1

Answer 2

thanks