# Math

posted by .

Differentiate f(x)= (8-2x)^3(x^2+1)^5.

My ans is 2(8-2x)^2(x^2+1)^4(-3x^2-10x+37). Plz recheck my simplify ans.
-my simplify ans is not the same as wolfram but the long ans is same with wolfram-

• Math -

f' = 3(8-2x)^2 (-2) (x^2+1)^5 + 5(8-2x)^3 (x^2+1)^4 (2x)
= (8-2x)^2 (x^2+1)^4 (-6(x^2+1) + 5(8-2x)(2x))
= (8-2x)^2 (x^2+1)^4 (26x^2 - 80x + 6)
= -8(4-x)^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 -

I still don't get it how do u simplify from
= (8-2x)^2 (x^2+1)^4 (26x^2 - 80x + 6) to
= -8(4-x)^2 (x^2+1)^4 (13x^2 - 40x + 3) ... ?
What can i conclude from it is (4-x)^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 -

(8-2x)^2 = 4(4-x)^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 8-2x, so it looks more like the original syntax.

## Similar Questions

1. ### chem

an aq. solution(NaCl) made by using 133g diluted to a total solution volume of 1 L.Calculate the molarity, molality & mass % of the solution(density of solution = 1.08g/mL) [ans: M=1.92M, m=2.0m, 10.4 %] i need the calculation work …
2. ### Math

How to d/dx y= (9+((x-9)/6)^1/5)^1/2 ? Hope u can give me the way how to calculate it. ^^ I got 1/60 ((x-9)/6) ^ (-9/10), i think my answer is wrong because i check at wolfram website the ans is differrent from mine (sorry i didn't
3. ### Math

Calculate dy/dx, (x^3)(y^7) + 16xy^6=0 My ans is (y(-16-3x^2y))/ x(96+7x^2y) but at wolfram is y^6(3x^2y+16). Btw i use product rule to dy/dx. Need someone to recheck my ans.
4. ### Math

How to differentiate e^e^x? Ans at wolfram is e^(x+e^x). I need the calculation method.
5. ### Math

Differentiate ln (1+ cos x)... My ans is (-sin x)/ (1+cos x), but at wolfram is -tan (x/2). I think they simplify it but how did they do it?
6. ### math

use implicit differentiation to find dy/dx and then d^2y/dx^2. y^2=ye^x^2+2x ans for dy/dx= [2(xye^x^2 + 1)]/(2y-e^x^2) after that i don't know how to proceed. can someone show me the steps(x need for calculation) and final answer. …
7. ### Math For College Readiness

Simplify the Complex Fractions 1. 8a / 3b^2 / 6ab /5 2. 42x^2 + 14x / x - 7 / 2 + 6x / 21 - 3x 3. 9 + 3 / x / x / 4 + 1 /12 4. (x^-1 + x^-2)divided by (9x^-2) Ans. #1: 20 / 9 Ans. #2: 42x^2 + 6x + 4 / -2x + 14 Ans. #3: 144 / x / 3x …