Question

prove 1-cos square theta by sin square theta is equal to 1

Answer 1

sin^2Ф + cos^2Ф = 1
sin^2Ф = 1 - cos^2Ф

So,
(1 - cos^2Ф)/sin^2Ф   
= sin^2Ф/sin^2Ф       [sin^2Ф = 1 - cos^2Ф]
= 1
Hence, proved.
Hope it helps :)
['^' means power and Ф is used for theta]
(though Ф is phi and not theta, i used as i couldn't find theta)