y=3sin(x+10)+5sin(x+70) =3sin(x+10)+5sin(x+10+60) =3sin(x+10)+5sin(x+10)*cos60+5cos(x+10)sin60 =11/2*sin(x+10)+5√3/2*cos(x+10) 所以最大值=√((11/2)^2+(5√3/2)^2) =√(121/4+75/4) =√(196/4) =√49 =7...