Question

POR FAVOR GALERA AJUDA URGENTE!!!!!​

Answer 1

sen²x + cos²x = 1

(3/4)² + cos²x = 1

cos²x = 1 - (3/4)²

cos²x = (1 + 3/4)(1 - 3/4)

cos²x = 7/4 × 1/4

cos²x = 7/4²

cosx = √7/4

sen(x + x) = 2 × 3/4 × √7/4

sen(x + x) = 3/2 × √7/4

sen(x + x) = 3√7/8

Resposta: a)3√7/8