Question

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

Answer 1

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