# Find f(x) from f"(x)

• May 4th 2013, 04:48 PM
noork85
Find f(x) from f"(x)
can someone please check to see which ne is correct? i was going over my homework and realized i may have done them wrong.

https://www.dropbox.com/s/9ozxqd2blr...2020.46.49.jpg (i think is wrong)

https://www.dropbox.com/s/ss9hsvvidx...2020.44.47.jpg (i think is right)
• May 4th 2013, 06:06 PM
LinearOperator
Re: Find f(x) from f"(x)
To find f(x) from f'', you simply integrate the function with respect to which ever variable you're working with. For instance, if you were working with

f''(x) = x
f'(x) would be x^2/(2)
and hence

f(x) would be f^3/(6)
• May 4th 2013, 06:21 PM
Prove It
Re: Find f(x) from f"(x)
Why do you think the first one is wrong? It's correct...
• May 4th 2013, 06:56 PM
noork85
Re: Find f(x) from f"(x)
and the second one is wrong?

ETA: can someone please explain anyway? thanks
• May 4th 2013, 11:10 PM
LLLLLL
Re: Find f(x) from f"(x)
No the first one is wrong. You plugged in 1 instead of 0 for x when you solved the first derivative. (I didn't read the whole thing so I don't know if you also did that when you solved f(x) or not
• May 4th 2013, 11:20 PM
noork85
Re: Find f(x) from f"(x)
exactly why i thought the first one was wrong....thanks.
• May 5th 2013, 08:42 AM
jpritch422
Re: Find f(x) from f"(x)
disregard