Question

Let f(x) = ln(x+(1/x)). f'(x) = (x^2 - 1)/ (x^3 + x). Find the x-coordinate of the point(s) on f at which the tangent to f is horizontal.

Answer 1

horizontal tangent -> slope=0
(x^2 - 1)/ (x^3 + x)=0

Answer 2

Okay I get that a horizontal tangent means the slope is zero but that doesn't tell me anything.

Answer 3

the derivative of a function f(x) is the slope of the tangent line touching (x,f(x))

Answer 4

wait scratch that just figured it out!

Answer 5

:)

Answer 6

Thanks so much :)!