Question

Prove that sin square A + sin square A - tan square A = tan square A ??

Answer 1

`sin ^2 A+ sin ^2 A - tan ^2 A = tan ^2 A` is equivalent to `sin^2 A = tan^2 A`. Unfortunately it
isn't true, as `A=45^circ` provides an easy counterexample.

Explanation:

That says show

`sin ^2 A+ sin ^2 A - tan ^2 A = tan ^2 A`

That can't possibly be true. Let's try `A=45^circ`

`(1/sqrt{2})^2 + (1/sqrt{2})^2 - 1^2 = 1/2 + 1/2 -1 = 0`

That's not equal to `tan^2 A = 1`.