Question

How do you prove `cos^2phi/cos^2theta=(1+cos2phi)/(1+cos2theta)`?

Answer 1

see below

Explanation:

`cos^2 phi/cos^2 theta = (1+cos 2 phi)/(1+cos2theta)`

Right Side: `= (1+cos 2 phi)/(1+cos2theta)`

`=(1+2cos^2phi-1)/(1+2cos^theta-1)`

`=(2cos^2 phi)/(2cos^2theta)`

`=cos^2phi/cos^2theta`

`=`Left Side