Friday

March 6, 2015

March 6, 2015

Posted by **mathstudent** on Sunday, January 6, 2008 at 11:30pm.

- calculus -
**Reiny**, Monday, January 7, 2008 at 12:28ammessy, are you sure you typed correctly?

I was hoping the bottom would factor so I could use partial fractions.

the way it stands I ran it through an integration program to get

(√10/10)[tan^{-1}[√10(x+1)/5]

are you working at that sophisticated level of integration??

Is this highschool level ??

- calculus -
**Count Iblis**, Monday, January 7, 2008 at 9:19amYou can just write the denominator as:

2x^2 + 4x + 7 =

2 (x^2 + 2 x + 7/2) =

2 [(x + 1)^2 + 5/2]

Then you use the fact that the integral of dx/(x^2 + a^2) = 1/a arctan (x/a)

So, the integral is:

1/2 1/sqrt(5/2) arctan[(x+1)/sqrt(5/2)]=

Answer given by Reiny above.

- calculus -
**mathstudent**, Monday, January 7, 2008 at 11:34amThanks Reiny + Iblis!

This is from Wiley textbook "Calculus: Early Transcendentals Combined, 8th Edition", section 8.4. I think problem #41 (from memory).

I typed it right. The answer you two wrote matches the book, however I couldn't figure out how to do it. Makes sense now. Thanks

Reiny, thanks for writing that. I feel like an idiot getting stuck on these textbook problems sometimes.

**Answer this Question**

**Related Questions**

Integral calculus - Please do help solve the followings 1) Integrate e^4 dx 2) ...

calculus - 1) Integrate Cos^n(x) dx 2) Integrate e^(ax)Sinbx dx 3) Integrate (...

Calculus - 6.] Replace the integral in exercise 5 (int. (1/ 1 – t) dt a = 0, b...

calculus 2 - Justify, with a written explanation or a mathematical reasoning ...

Calculus AB - Please help me integrate this equation using partial fractions: ...

Calculus - How do you integrate [(x^2)(cos(2(x^3)))]? I tried to integrate by ...

calculus help please - dy/dx = 2y^2 Integrating...y=2/3 y^3 + C put 1,-1 into ...

calculus - 1) Integrate (e^x+x)^2(e^x+1) dx 2) Integrate xe^x2 dx Let u=(e^x+x) ...

Calc 1 - integrate from 0 to pi/4 (sec^2x)/((1+7tanx)^2)^1/3 integrate form pi^2...

integrate - integrate du/3u and integrate x/x^2 dx it might be simple...i just ...