Write the first derivative of the given function.
f(x) = x^2[ln(x)]^14
I got f '(x) = 2x(lnx)^13 + (7+lnx)

For which x-values does f(x) have horizontal tangents? (Enter your answers as a comma-separated list.)
x =

Question

Write the first derivative of the given function. 
f(x) = x^2[ln(x)]^14
I got f '(x) = 2x(lnx)^13 + (7+lnx)

For which x-values does f(x) have horizontal tangents? (Enter your answers as a comma-separated list.)
 x =

anonymous · Answer

14 x (lnx)^13+2x(lnx)14

anonymous · Answer

yeah same thing, I just pulled out the common factor

anonymous · Answer

2x(lnx)^13(7+lnx)

anonymous · Answer

not +(7+lnx)

anonymous · Answer

Oh sorry, yeah I have that on my paper here I typed it wrong
my real issue is finding where F'(x)=0

anonymous · Answer

not a problem 2x(lnx)^13(7+lnx)=0
7=-lnx
7=ln(1/x)
e^7=1/x
x=1/e^7

anonymous · Answer

I tried that but apparently it's wrong
:(

zepdrix · Answer

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Hmm do these work maybe? :O