Calculus
posted by Jessica .
Determine the absolute extreme values of f(x)=4√x 2x on the interval [1,4]
I found the derivative of f(x)=4√x 2x
f'(x)=2/x^(1/2)  2

I have no idea what to do now.

Since you have found your derivative you then need to move on and find its critical values(where the derivative equals zero). Then if those numbers are within the interval [1,4] you must also plug those into your orignal function. If they do not, then they should be disreguarded and thrown out
F(1)= 2/(1^(1/2)2=0 giving you the point (1,0) which is your max
F(4)= plug the 4 into your x value for your derivative and you should get 1