## anonymous 3 years ago Find the error in my steps? Q: x = 4 + te$$^t$$, y = (t$$^2$$ + 1)e$$^t$$, 0 ≤ t ≤ 3 Set up an integral that represents the area of the surface obtained by rotating the given curve about the X-axis. Now to post my work...

1. anonymous

It's #6

2. anonymous

|dw:1342035220350:dw|

3. anonymous

I solved it before so look at that my answer was right in there.

4. anonymous

Ack... Let me see where that line is and what I subsituted

5. anonymous

Wait what? No that's not incorrect what I wrote @mahmit2012 , I just divided both sides by dt before I made the subsitution

6. anonymous

I replaced $$\large\frac{dx}{dt}$$ with te$$^t$$

7. anonymous

|dw:1342035678669:dw|

8. anonymous

|dw:1342035759311:dw|

9. anonymous

Ah the definite integral gives the correct value I need now! Well done!

10. anonymous

I was missing a term I seems