Find the maximum and the minimum values, if any, without using derivatives of the following functions:
f(x) = |sin 4x + 3| on R
We know that – 1 ≤ sin4x ≤ 1
= 2 ≤ sin4x + 3 ≤ 4
= 2 ≤ |sin 4x + 3| ≤ 4
Hence, the maximum and minimum value of f are 4 and 2 respectively.