By first applying the Product Rule, choose the option that gives (correct

to two decimal places) the overall maximum value of the function
f(x) = e^3x cos(2x)
on the interval [1/12 π, 1/4π].
Options
A 0.49 B 1.90 C 2.19 D 2.42
E 3.97 F 5.88 G 7.46 H 10.55

f'(x)=e^3x(3cos(2x)-2sin(2x))=0

3cos(2x)=2sin(2x) divide by 2cos(2x)
tan(2x)=1.5 x=0.4914(rad)
f(0.2618)=1.90
f(0.4914)=2.42 <---
f(0.7854)=0