Find the first and second derivative of the function. Check to see that your answers are reasonable by comparing the graphs of
f, f ', and f ''.
f(x) = e^x − x^7

Question

Find the first and second derivative of the function. Check to see that your answers are reasonable by comparing the graphs of 
f, f ', and f ''.
f(x) = e^x − x^7

anonymous · Answer

i know the first derivitive is $$f'=e ^{x}-7x ^{6}$$

anonymous · Answer

You can apply the sumrule and add the derivatives of 
$$e^x$$ 
and
$$−x^7$$

anonymous · Answer

Yes you've got that one right

Now you can apply the Sum Rule again

abdullah1995 · Answer

$$f''= e^x -42x^5$$

anonymous · Answer

Are you allowed to use software to draw your graphs?

The second derivative is perfect

anonymous · Answer

i thought so too @abdullah1995 but it said it was wrong when i submitted my answer.

anonymous · Answer

or do you have to analyse the functions to draw them?

anonymous · Answer

@abster i can plug it in the calculator

anonymous · Answer

I'm pretty sure you've got them right

anonymous · Answer

http://rechneronline.de/function-graphs/ is a nice site to plot graphs

anonymous · Answer

okay thanks! i forgot to put an x when i submitted it. it was right. @abdullah1995

anonymous · Answer

thanks for helping too! @abtser

abdullah1995 · Answer

no worries :)

anonymous · Answer

Sorry,
got the graphs

where f' is 0 there are maxima or minima in f

where f´ is 0 , f' has its extremes

anonymous · Answer

Ok, nice that you can see where it was wrong
although tough that a typo spoilt it