Given f(x) = cosx, 0≤x≤4pi, sketch and give range in each case

a) y = 2f(x) + 1

range of -1≤y≤3

b) y = f(2x)

squeezed along x axis so there are 8 turning points, range of -1/2≤y≤1/2

c) y = -f(x)

same range, simply turned over

d) y = f(x + pi)

same range, graph is moved 1pi to the left

Are these right??? :/