What's the maximum value (M) and the minimum value (m) of the expression P=1-2|cos3x|?

Question

A. M = 3; m = -1.

B. M = 1; m = -1.

C. M = 2; m = -2.

D. M = 0; m = -2.

Sidenote: Please explain your answer. Thank you!

Answer 1

Thomas, notice that the mIn and max of cos are -1 and 1 respectively.

Then the absolute value of a cosine has mIn and max of 0 and 1, respectively.

Now you should be able to calculate the mIn and max values of P.