у=х^(1/6), у'=(1/6)*х^(1/6-1)= (1/6)* х^(-5/6)= 1/(6*корень6из(х^5))
sin75 cos30-sin30 cos75=sin(75-30)=sin45=√2/2
№1. 1) Р1=5.5*4=7(см)