Вычислите: a] sin 15° b] cos88° cos2° — sin88° sin2° c] sin50° cos5°…

a) sin15*=sin (45-30)=sin45*cos30*- cos45*sin30=sqrt (2) /2*sqrt (3) /2 — sqrt (2) /2*1/2=sqrt (2) (sqrt (3) -1) /4 b) cos (88+2)=cos (90*)=0c) sin (50-5)=sin (45*)=sqrt (2) /2