MATLAB Integration Situation

Question

I want to evaluate the integral of this function :

(cos(t^2)*sin(t)^2)^(1/2)

over the period

-15*pi:50*pi

I am using these :

f=@(t) (cos(t.^2).*sin(t).^2).^(1/2);
quad(f,-15*pi,50*pi)

But i am getting warned:

Warning: Maximum function count exceeded; singularity likely.
> In quad at 110
In PPEL at 6

ans =

35.8252 +54.5673i

Most likely there is something stupid that i don't know about the theoretical part of the math, like some singularity as MATLAB said.

Moreover, when i want to evaluate this function sybolically with this :

int((cos(t.^2).*sin(t).^2).^(1/2))

It says : Warning: Explicit integral could not be found.

ans =

int((cos(t^2)*sin(t)^2)^(1/2), t)

What's the solution ?

Is your function really supposed to be the square root of (the multiplication of the (cos of the square of t) and the (square of the sin of t))? — Mark Elliot, Apr 04 '12 at 02:31

score 2 · Answer 1 · answered Apr 04 '12 at 01:36

2

Plot the function without trying to do the integral.

What I notice is that you are going to be taking the square root of a negative number. I suspect that that isn't what you want to be doing...

answered Apr 04 '12 at 01:36

PearsonArtPhoto

1 Answers1