Question

Question #befa7

Answer 1

To verify one should change only one side by using identities and axioms, until it is identical to the other side.

Explanation:

Given: `sin^2(x)cos^2(x)+cos^4(x)=cos^2(x)`

Remove a common factor of `cos^2x` from the terms on the left:

`(sin^2(x)+cos^2(x))cos^2(x)=cos^2(x)`

Use the identity `sin^2(x)+cos^2(x) = 1`

`(1)cos^2(x)=cos^2(x)`

The one can be dropped:

`cos^2(x)=cos^2(x)` (Q.E.D.)