SOLUTION: Hello! I am trying to figure out these integrals but I keep getting stuck. (also, not sure how to write the integral symbol in the editor on here, so hopefully my question makes

Algebra ->  Functions -> SOLUTION: Hello! I am trying to figure out these integrals but I keep getting stuck. (also, not sure how to write the integral symbol in the editor on here, so hopefully my question makes      Log On


   

Question 1026953: Hello!
I am trying to figure out these integrals but I keep getting stuck. (also, not sure how to write the integral symbol in the editor on here, so hopefully my question makes sense).
1. integral: +%28+%286+%29+%2F+sqrt%289x%5E%282%29+-1%29+%29+dx+
I tried U-substitution but got stuck...not sure if I did it right or not.
+u=9x%5E%282%29-1+
+du=18x+dx+%2B+c
+dx+=+%28du%2F18x%29+
2. integral: +%28+3%5E2x%2F%281%2B3%5E2x%29+%29+dx+
Thank you, in advance!
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
This site supports some basic LaTeX commands, and you can type it out as such:



Here, a simple u-substitution probably won't work since there is no x term (u = 9x^2 - 1, du = 18x dx - if the integral had been 6x instead of 6, then a u-substitution works).

I don't know if you learned about using a trigonometric substitution, but you can use the substitution , and using the fact that .

2. Do you mean
?

If so, you can do a u-substitution.