# MATLAB Setting up Newton Raphson integral with matlab

1. Jan 22, 2009

### Moly

Hi All.

I have an equation that i want to numerically find the root of by using Newton Raphson. However the equation involves an integral which i am using the trapazoidal rule to evaluate. And here is the simplified version of it:
$$1 = e^{-cy} \int_0^1 e^{-y(1-x)} dx$$

So i am supposed to integrate for x and then solve the resulting equation for values of y. How do i do that????????????

If i just wanted to do the integration, i would have used "syms" and found the result in terms of y.... but i am totally stumped with this... plz... SOS!!!!!!!

2. Jan 23, 2009

### Gib Z

Well, look inside the integral. The variable is x, y is a constant inside the integral. We can easily solve that integral exactly, no need to approximate that integral.

After that, you will have on the RHS some exponential terms divided by y, which is easy to apply Newtons Method to.

3. Jan 25, 2009

### Moly

Thanks Gib.
I figured where i went wrong.. i still have a question that i will post later today