How do you find the derivative 1/(x^7 + 2)1x7+2?

3 Answers
May 24, 2015

I would usr the Quotient Rule as:
f'(x)=(-7x^6)/(x^7+2)^2

Remember the Quotient Rule to derive a function f(x)=(g(x))/(h(x))
you get:
f'(x)=(g'(x)h(x)-g(x)h'(x))/[h(x)]^2

May 24, 2015

To find the derivative of f(x) = 1/(x^7 + 2) you would use the quotient rule:

f(x) = g(x)/(h(x)) then f'(x) = (g'(x)h(x) - g(x)h'(x))/(h(x)^2)

Thus:

let g(x) = 1 so g'(x) = 0

let h(x) = (x^7 + 2) so h'(x) = 7x^6

Therefore we get that:

f'(x) = (-7x^6)/(x^7 + 2)^2

this shows us that f(x) is always decreasing, as its derivative is always negative

May 25, 2015

I would not use the quotient rule. (There's no difference in the answer, but this is how I think about this differentiation.)

I would use the chain rule:

f(x)=1/(x^7+2) = (x^7+2)^-1

f'(x) = -1(x^7+2)^-2 * 7x^6

= (-7x^6)/(x^7+2)^2