Step-by-step explanation:
Step 1: From the given equation, taking the Left Hand Side (LHS) of the equation
Step 2: Simplify the LHS to make it equal to the Right Hand Side (RHS)
LHS = sin^4x - cos^4x = (sin²x)² - (cos²x)²
= (sin²x - cos²x)(sin²x + cos²x)
= sin²x - (1 - sin²x) since sin²x + cos²x = 1
= 2 sin²x - 1
= RHS
Hence proved.
