Posted by Ifi on Sunday, October 28, 2012 at 4:44am.
Differentiate f(x)= (82x)^3(x^2+1)^5.
My ans is 2(82x)^2(x^2+1)^4(3x^210x+37). Plz recheck my simplify ans.
my simplify ans is not the same as wolfram but the long ans is same with wolfram

Math  Steve, Sunday, October 28, 2012 at 6:16am
f' = 3(82x)^2 (2) (x^2+1)^5 + 5(82x)^3 (x^2+1)^4 (2x)
= (82x)^2 (x^2+1)^4 (6(x^2+1) + 5(82x)(2x))
= (82x)^2 (x^2+1)^4 (26x^2  80x + 6)
= 8(4x)^2 (x^2+1)^4 (13x^2  40x + 3)
which is what Wolfram gets.
Watch for those pesky chain rule factors and minus signs. 
Math  Ifi, Sunday, October 28, 2012 at 8:20am
I still don't get it how do u simplify from
= (82x)^2 (x^2+1)^4 (26x^2  80x + 6) to
= 8(4x)^2 (x^2+1)^4 (13x^2  40x + 3) ... ?
What can i conclude from it is (4x)^2 &(13x^2  40x + 3) is divided by 2 . Then (x^2+1)^4 is not simplified by any no. Lastly, why do u put 8? if u try to expand it back it didn't get the same ans. 
Math  Steve, Sunday, October 28, 2012 at 11:55am
Really. Forgotten your algebra I?
(82x)^2 = 4(4x)^2
The intervening two lines should have had a "" sign in front, from the (2) factor. My typo. No need to pull out the 8; just felt like it. Prolly should leave it as 82x, so it looks more like the original syntax.