Question

Упростите 1)cos(t-x)- sintsinx 2)1/2cost - sin( П/6+t)

Answer 1

$cos(t-x)-sintsinx=costcosx+sintsinx-sintsinx=costcosx;\\\\ \frac{1}{2}cost-sin(\frac{\pi}{6}+t)=\frac{1}{2}cost-sin\frac{\pi}{6}cost-cos\frac{\pi}{6}sint=\\ \frac{1}{2}cost- \frac{1}{2}cost-\frac{\sqrt3}{2}sint=-\frac{\sqrt3}{2}sint.$