Prove this: 1−sin4x−cos4x1−sin6x−cos6x=23?
1−sin4x−cos4x1−sin6x−cos6x=23
2 Answers
Proved
In step 3 the following formulae are used
and
Please see the explanation. I confirmed each step of this proof using www.WolframAlpha.com
Explanation:
Multiply both sides by
Substitute
Multiply the square:
Distribute the -3:
Combine like terms:
Divide both sides by 2:
Substitute
Expand the cube:
Distribute the -1:
Combine like terms:
The right is identical to the left. Q.E.D.