Question

Identify the maximum and minimum values of the function y = 10 cos x in the interval [-2π, 2π]. Use your understanding of transformations, not your graphing calculator.

Answer 1

for the function 10cosx, it's amplitude just increases by a factor of 10. that's it.
for any function, kcosx, where k is a positive constant, it stretches vertically by a factor k.
thus, the max of cosx in [-2pi, 2pi], is 1, and the min is -1.
the max and min of 10 cosx is just multiplying 10 with the min and max values.
finally the max value of 10cosx is 10 and the min value is -10

Answer 2

Ahh thank you (: