Question

How do I proceed to solve this equation?
sin(x)-cos^2(x)=0

Answer 1

hint: cos^2(x)=1-sin^2(x)

Answer 2

\[\sin(x)-(1-\sin^2(x))=0 \\ \sin^2(x)+\sin(x)-1=0\]
you have a quadratic in terms of sin(x) to solve

Answer 3

Many thanks! This is one of the properties of cos^2 I was not aware of.

Answer 4

It is a Pythagorean identity.
sin^2(x)+cos^2(x)=1