Determine the values of x where the tangent line is horizontal for the function:
f(x) = \frac{1}{(x^2 - 25)( x - 7)}.

The value(s) of x where the tangent line to the graph of the function is horizontal is(are) .
(If there aren't any x- values, then enter ``none'' in the answer space, and if there are more than one value, separate the values with a comma in the answer space.)

Question

Determine the values of x where the tangent line is horizontal for the function:
f(x) = \frac{1}{(x^2 - 25)( x - 7)}.


The value(s) of x where the tangent line to the graph of the function is horizontal is(are) .
(If there aren't any x- values, then enter ``none'' in the answer space, and if there are more than one value, separate the values with a comma in the answer space.)

anonymous · Answer

$$f(x) = \frac{1}{(x^2 - 25)( x - 7)}$$
let's find the derivative of f(x)...

anonymous · Answer

gimme the derivative.

anonymous · Answer

I just popped that into my TI 89 and I got
$$-(3x ^{2}-14x-25)\over(x-7)^{2}(x ^{2}-25)^{2}$$
I'm working on a similar question. Anyone please help. I appreciate it.

anonymous · Answer

I'm here...

anonymous · Answer

Hi, dpalnc. Can you solve the problem then? Much obliged.