Question

Вычислите: 2sin 19п/6 + ctg(-7.25п)+4cos^2 81п/6

Answer 1

$=2sin frac{7 pi }{6}-ctg frac{ pi }{4} +4cos^2 frac{3 pi }{2} =2*(- frac{1}{2} )-1+4*0=-2$

Answer 2

$2sin frac{19pi}{6}+ ctg(-7.25pi)+4cos^2 frac{81pi}{6}=2sin frac{7pi}{6}+ ctg(- 0.25pi )+4cos^2 frac{27pi}{2}=2sin frac{7pi}{6}+ ctg(- 0.25pi )+4cos^2 frac{27pi}{2}=2cdot( -frac{1}{2})+(-1)+ 4cos^2 frac{3pi}{2}=-1-1+4cdot0=-2$