求y=sin(x/2)+cos(x/2)在(-2派,2派)内的单调递增区间

Question

求y=sin(x/2)+cos(x/2)在(-2派,2派)内的单调递增区间

Answer 1

y=sin(x/2)+cos(x/2)=根2sin(x/2+派/4）,x∈(-2派,2派),(x/2+派/4）∈(-3派/4,5派/4),-派/2