Question

How do you solve `2sin^2theta-cos2theta=0`?

Answer 1

`2sin^2theta - (1 - 2sin^2theta) = 0`

`2sin^2theta - 1 + 2sin^2theta = 0`

`4sin^2theta = 1`

`sin^2theta = 1/4`

`sintheta = +-1/2`

`theta = pi/6 + 2pin, (5pi)/6 + 2pin, (7pi)/6 + 2pin and (11pi)/6 + 2pin`

Hopefully this helps!