Find the derivative of f(x) = -10/x at x = -12.

Question

anonymous · Answer

Lets find the derivative first

anonymous · Answer

Do you know how to find the derivative?

anonymous · Answer

no i dont know how

anonymous · Answer

Well if you remember from algebra |dw:1422593281344:dw|

anonymous · Answer

$$f(x) = -\frac{ 10 }{ x } \implies -10x^{-1}$$ now you can use the power rule

anonymous · Answer

Can you find the derivative of that?

anonymous · Answer

im not really sure what to do with that to be honest

anonymous · Answer

$$nx^{n-1}$$ that's the power rule, apply that.

anonymous · Answer

Bring down -1 and -1 from -1

anonymous · Answer

That's all it is saying

anonymous · Answer

im still confused :( im sorry but what do i do with the 12?

anonymous · Answer

12?

anonymous · Answer

-12*

anonymous · Answer

You plug it in after you find the derivative

anonymous · Answer

f'(12)

anonymous · Answer

im still confused on the first part then

anonymous · Answer

-12*

anonymous · Answer

Mhm, well can you show me how you would use the power rule.

anonymous · Answer

That's all there is, it's just a basic algebra rule and a very easy derivative rule, try it out first before you quit :P

anonymous · Answer

10x^-1 so is it just 1/10 @iambatman

anonymous · Answer

No, $$f(x) = -10x^{-1} \implies f'(x) = 10x^{-2} = \frac{ 10 }{ x^2 }$$ using the power rule now you just have to plug in the -12, I suggest you look up algebra rules and exponent rules :)

anonymous · Answer

OH that was simple thank you so much! do you mind helping me with another one?