anonymous 4 years ago How can I solve the following? (attached)

1. anonymous

2. anonymous

Sample problem:

3. anonymous

What step are you confused on the sample problem?

4. anonymous

I understand the sample problem. I just don't know how to use it for the actual problem.

5. anonymous

do the same...instead of using 7 use 5

6. anonymous

I did, but it shows up as wrong when I put it in.

7. anonymous

then you did something wrong. ...show me the steps

8. anonymous

what is the final answer that you got when you did the problem?

9. anonymous

Nevermind, I found my error, instead of 2/9 I put 2/5. Sorry. Can you help me with another problem though?

10. anonymous

yes sure....remember to follow all the steps and make sure you don't make a mistake. One small mistake can make the answer wrong

11. anonymous

12. anonymous

Sample:

13. anonymous

What's the first step? Let's make the square root into an exponent $\int\limits_{3}^{7}\frac{1}{\sqrt{6x+7}}dx$$\int\limits_{3}^{7}\frac{1}{(6x+7)^\frac{1}{2}}dx$

14. anonymous

then we bring the denominator to the top. But in order to do this we have to make the exponent a negative. Then we get $\int\limits_{3}^{7}(6x+7)^{-\frac{1}{2}}dx$

15. anonymous

You just integrate what's inside first....can you tell me what you get?

16. anonymous

3x^2+7x+C

17. anonymous

No that's not it. Look back in the problem you did before and see how they integrated a square root after it became $(-------)^\frac{1}{2}$

18. anonymous

you have to do the chain rule.

19. anonymous

Try it one more time....what is the integral?

20. anonymous

I have no idea here..

21. anonymous

I thought you know how to integrate something that was a square root. Look at the example problem you did before and see what happens.

22. anonymous

Would it be: 1/12 root of 6x+7?

23. anonymous

Is the answer 1/4? If yes, then I've done my work correct.

24. anonymous

I think you made a mistake $\frac{1}{6} *\frac{1}{2}=\frac{1}{12}$ that's how you got the 12 right?

25. anonymous

Yes

26. anonymous

it's suppose to be$\frac{1}{6}*2=\frac{2}{3}=\frac{1}{3}$

27. anonymous

1/3 root of 6x+7 not 1/12 root of 6x+7

28. anonymous

Oh, so then the answer would be: 1.

29. anonymous

what no I got something else

30. anonymous

$\frac{1}{3}\sqrt{6x+7}$$\frac{1}{3}\sqrt{6(7)+7}-\frac{1}{3}\sqrt{6(3)+7}$

31. anonymous

$\frac{1}{3}(\sqrt{6(7)+7}-\sqrt{6(3)+7})$$\frac{1}{3}(\sqrt{42+7}-\sqrt{18+7})$

32. anonymous

can you do the rest?

33. anonymous

Yes, I got it.

34. anonymous

what did you get?

35. anonymous

Im doing the math right now.

36. anonymous

ok tell me what you get just to check if you got it right.

37. anonymous

2/3

38. anonymous

yeah that's what I got good job.

39. anonymous

If you have more problems post them in a different question.

40. anonymous

I want to give you more medals :) for the good job