Question

qual e o valor de A=sen70.cos20+sen20.cos70​

Answer 1

Resposta:

senacosb + senbcosa = sen a + b = sen 70 + 20 = sen 90 = 1

Explicação passo-a-passo:

Answer 2

Se sen(a+b)=sena.cosb+senb.cosa

Então sena.cosb+senb.cosa=sen(a+b)

Daí

sen70.cos20+sen20.cos70=sen(70+20)

A=sen(90)=1