When a= 1, b= 1, and -4asin(bX/2)=-4sin(x/2), the maximum value is 4, x=4kπ-π, and the minimum value is -4, x=4kπ+π.

When a= 1, b=- 1 and 4asin (bx/2) =-4s in (-x/2), the maximum value is 4, x=4kπ+π, and the minimum value is -4, x = 4kπ-π.