PDA

View Full Version : Max value f(x)=3sin(3x) 4cos(3x)


amy440
Dec 7, 2011, 10:53 PM
Can anybody solve f(x)=3sin(3x) 4cos(3x) by algebraically with trig identically...

ebaines
Dec 8, 2011, 07:32 AM
Are you asking to find the maximum value of


f(x) = 3 \sin(3x) + 4 \cos(3x)
?

The max value can be found by taking the derivative of f(x) with respect to x and setting it to zero. When you do this you'll get an expression for tan(3x) that produces a maximum, and from that can find the corresponding value for f(x). Hope this helps.

amy440
Dec 8, 2011, 07:40 AM
Hi Ebaines,

I have to solve it by trig identity. Can u give me any idea how to solve it that way...

Thanks in advance...

Amy