Trig function appears awkward to integrate


by Edmundb
Tags: appears, awkward, function, integrate, trig
Edmundb
Edmundb is offline
#1
Feb17-13, 07:07 AM
P: 2
I hope this isn't too simple for the maths forum.

I'm trying to find the length of the locus described by the bottom of a garage door as it is raised. It's all fairly straightforward until I have to integrate a function of the form

√ (sin2θ + k cos2θ)

k does not depend on θ. I tried several approaches to the problem and always came back to the above function.

In the end I integrated numerically and got my number which checks with reality. There's probably some nifty substitution but just I can't find it.
Phys.Org News Partner Science news on Phys.org
Lemurs match scent of a friend to sound of her voice
Repeated self-healing now possible in composite materials
'Heartbleed' fix may slow Web performance
JJacquelin
JJacquelin is offline
#2
Feb17-13, 07:32 AM
P: 744
See at the elliptic functions.
http://mathworld.wolfram.com/Ellipti...econdKind.html
Edmundb
Edmundb is offline
#3
Feb17-13, 08:56 AM
P: 2
Thank you very much indeed. That looks like the clue I need. (As you've probably gathered I'm an Engineer and not a mathematician.)


Register to reply

Related Discussions
Spiked Math: The Awkward Function Science Comics 0
trig substitution: integrate sqrt(16+x^2) over x Calculus & Beyond Homework 3
Function that counts the number of times a specific character appears in a string Programming & Computer Science 2
Function to count the number of times a specific word appears in a string Programming & Computer Science 6
Integrate using trig substitution Calculus & Beyond Homework 6