Answer:
see explanation
Explanation:
Using the identity
sin²x + cos²x = 1
Consider left side
(2sinx + 3cosx)² + (3sinx - 2cosx)² ← expand parenthesis using FOIL
= 4sin²x + 12sinxcosx + 9cos²x + 9sin²x - 12sinxcosx + 4cos²x
Collect like terms
= 13sin²x + 13cos²x ← factor out 13 from each term
= 13(sin²x + cos²x)
= 13 × 1
= 13
= right side , thus proven