I'm supposed to find the length of the curve.

[afcwestwarrior]

I got up to here. L = ∫ √(1 + sec^4 (t)) dt

oh yea it's from 0,<= t <= pi/4

do I have to pull a sec^2 t out or do I just square it, I don't think I can use the square root yet unless is was just sec^4 t by itself.

I need help man.

 

[gabbagabbahey]

I got up to here. L = ∫ √(1 + sec^4 (t)) dt

This integral cannot be expressed in terms of elementary functions

Are you sure that your steps leading up to this point are correct? What was the original problem?

 

[afcwestwarrior]

The original problem was r(t)= < sin t, cos t, tan t> 0 <= t <=pi/4

It asked me too find the length of the curve to four decimal places. It told me to use my calculator to approximate the integral.

 

[afcwestwarrior]

They also came up with an answer. L = 1.2780

 

[gabbagabbahey]

Okay, then you've come up with the correct integral. However, it is much easier to evaluate numerically than to try it analytically.

What numerical approximation methods have you been taught? Apply one of them.

 

[afcwestwarrior]

So I just plug in the values o and pi/4

 

[afcwestwarrior]

I don't think I've been taught any numerical approximation methods yet. We barely went through this section.

 

[afcwestwarrior]

Wait a minute. Wouldn't I use series or something.

 

[afcwestwarrior]

What method would you use.

 

[gabbagabbahey]

I would probably use either the Trapezoid rule, or Simpson's rule...have you been taught either of those?