Question

show that sin(40+x)cos(10+x)-cos(40+x)sin(10+x)=1/2​

Answer 1

Step-by-step explanation:

taking left hand side

$\sin(40 + x) \cos(10 + x) - \cos(40 + x) \sin(10 + x) \\ we \: know \: that \: this \: is \: sin(x - y) \: fourmula \\ \sin(40 + x - (10 + x)) \\ \sin(40 + x - 10 - x) \\ \sin(30) \\ \frac{1}{2} \: heance \: prove$