Recent content by HolyDesperado

I figured it out, it's Integral[0->1/8] (1/2*(2 e^(0.9theta))^2)dTheta thanks everyone

i thought it meant arclength, but i guess it is area so it should be int [a->b] of (1/2(r)^2)dthetabut I still don't know how to set up this problem correctly

integrating from 0 to 1/8 is giving me .355, which isn't right =-\

are you talking about the inequality from 0 to 1/8? so my boundaries of int. are a=0, b=1/8?

Homework Statement Find the area enclosed by the polar curve r = 2 e^(0.9theta) on the interval 0 <= theta <= 1/8 and the straight line segment between its ends. Homework Equations arclength = The Attempt at a Solution I need help finding the boundaries for this problem...

Thank you, I see my error now and the suggestion lead me to a correct answer.

Homework Statement Assume that sin(x) equals its Maclaurin series for all x. Use the Maclaurin series for sin(7x^2) to evaluate the integral https://webwork.math.lsu.edu/webwork2_files/tmp/equations/f4/767c0643696d085d77f9a697294a311.png Your answer will be an infinite series. Use the first...

Yes, your final answer should be sec^4x/4, but you forgot one thing: +C. This is important.

I left off the two at the end when I entered my solution, and webwork counted that as incorrect. I just tried your solution with the extra 2 and now it is correct. Silly webwork. =) Thanks for you patience throughout helping me find this solution. Hopefully we can do business again in the future!

Sure, here is what I've done below: http://img261.imageshack.us/img261/9651/mathhelp.jpg

Ah, I see it more clearly now, but once I plug in x, which is .1, I should get (-4)^n*(0.1)^(4n+1)/(4n+1)n! I then plugged in 0 and 1 for n to test the first two terms of the series, but my answer came out wrong again. =( Please help.

By integrate the powers you mean -4^n*x^(4n) = -4^(n+1)*x^(4n+1)/(4n+1)n! ...?? Sorry, English is not my native tongue.

so you're saying I should get (-4x)^(4n+1)/(4n+1)n! ... ?

I'm afraid I don't understand. Can you elaborate on this please?

Hey Dick sorry for the late reply, I had to run out real quick, but I tried your suggestion of (-4x^4)^n. However, I am still getting an incorrect answer. I brought out -1/n! and then integrated (4x^4)^n. Which should give me 4^nx(x^4)^n/4n+1?