Question

Can someone please teach me on how to create a script in Scilab that would evaluate for an intersection on point of two given functions and plot the functions. Thank you :)

Answer 1

oh :(

Answer 2

well.. it seems there is a function `fsolve()` for that. I played with it a little and got this:
```
deff('res=f1(x)','res=3*x')
deff('res=f2(x)','res=sin(x)+3')

deff('res=fsol(x)','res=f2(x)-f1(x)')
x0 = 0.
xsol =fsolve(x0,fsol)

edge = 4
x = linspace(-edge,edge,51)

scf(1)
clf(1)

plot(x,f1,'r-');
p = get("hdl"); p.children.thickness = 3;
plot(x,f2,'b-');
p = get("hdl"); p.children.thickness = 3;
xgrid(1, 1, 7)
```
at the end `xsol` should have the x-value of the intersection.
For that code I got the attached graph and `xsol=1.32` which makes sense:
http://www.wolframalpha.com/input/?i=sin%28x%29+%2B+3+%3D+3x

I did some more reading here:
http://www.openeering.com/sites/default/files/Nonlinear_Systems_Scilab.pdf
It says that `fsolve()` is based on Newton's method to find the 0 of the given function.
That means that it's not a magic function that can solve anything.. you have to take into consideration whether it can solve `fsol(x)` using the given `x0` or not.

Anyway, I hope it helps =)

Answer 3

@pitamar and @DavidUsa thank you :)