How do you verify #cos^4x - sin^4x = 1 - 2sin^2x#?
3 Answers
As below:
Explanation:
Note that
To prove that
I'll start with the left-hand side and manipulate it until it looks like the right-hand side using these two identities:
That's the proof. Hope this helped!
See below
Explanation:
To verify:
Let
Undo substitution: