SHE 8.4

[CooLiBoP]

Answer Check[/u]

6. -sqrt(4 - x²) + C

12. ln|(a² + x²)|^1/2 + C

34. ln|[sqrt(x² + 4x + 13)/(x + 2)]³| + C

[BlingBling]

I've got the same for 6. however for the others I get:
12. 1/2ln(a² + x²)
You got ln|(a² + x²)/a| + C however this is the same as ln(a² + x²) + C as the /a part can be seperated and combined with the constant C.  So our answers are only off by a factor 1/2.

34. Sqrt(x² + 4x + 5)

I didn't use the book's wierd trig trick to do these since they all work a lot easier with u-substitution.

[Brutal_Chicken]

I got the same answers for the first two Bling but for 34 I got ln|secu + tanu| + C. I let (x+2)^2 = 9tan^2u and x + 2 becomes 3sec^2u after taking the derivative and dividing by 2. That's how it looked by doing it how the book says... but sqrt(x^2 + 4x + 13), you wrote + 5 btw, is so much simpler.

[Achilles]

hey blingbling, guys..
for 6) i got the same as blingbling and coolibop
for 12) i got the same thing as bling bling
for 34) blingbling don't you mean 1/2(lnSqrt(x^2 + 4x + 13)) + C? instead of just the sqrt of that , this question is similar to 12.

[Miss_Kranky]

I don't know about you guys, but I got sqr(x^2+4x+13) +C so... bla... (btw, this is for number 34)

[AngelLaura]

For 34, I got sqrt(x^2 + 4x + 13).
I used the u-substitution method instead of that crazy trig junk.

[Yingster]

6) - rt(4-x²) + C
12) 1/2 ln (a² + x²) + C
34) rt(x²+4x+13) + C

[Observer]

6.) -sqrt(4-x²) + C
12.) ln |(sqrt(a² + x²) / a)| + C
34.) sqrt( (x+2)² + 9)  + C

[R]

I managed to get 12 and 34 by substitution...

is that illegal?