Can you check my work? I got 4 but answer is -4.
Limit as b-infinity of the integral of 32x^7e^(-x^(8)) from x=0 to x=infinity...
I posted a picture of my work...
Can you tell me where I made my mistake and why the answer is 4 and not -4? Thanks!

Question

Can you check my work? I got 4 but answer is -4.
Limit as b->infinity of the integral of 32x^7e^(-x^(8)) from x=0 to x=infinity...
I posted a picture of my work...
Can you tell me where I made my mistake and why the answer is 4 and not -4? Thanks!

anonymous · Answer

attachment

anonymous · Answer

Just click on 12.bmp

anonymous · Answer

*****PLEASE NOTE! i MEANT TO SAY THE "REAL ANSWER IS 4" AND i GOT -4...SORRY FOR THE CONFUSION!

anonymous · Answer

I just dont understand why the answer is positive 4! uhg

nurali · Answer

$$\int\limits_{}^{}e^x=e^x+c$$
$$\int\limits_{}^{}e ^{-x}=-e ^{-x}+c$$

anonymous · Answer

Is that just a rule then I forgot?...when I took the derivative, it should have been a negative and not a positive?

anonymous · Answer

I was just remembering that e^anything = e^anything...but apparently not e^negative anything?

anonymous · Answer

ok...I suppose that was my only mistake then...I won't forget that rule again! thanks Nurali!