How to plot an integral

Asked by Marina Gonzalez

Marina Gonzalez (view profile)

on 15 Jun 2019
Latest activity Answered by Star Strider

Star Strider (view profile)

on 15 Jun 2019
Accepted Answer by Star Strider

Star Strider (view profile)

Hello!
I need some help plotting the following: This is what I have:
syms x
kw = 91371;
CaO= 1.81*10^(-4);
FaO= 0.1233;
K = 1.29;
fun =FaO*((1+K*CaO*(1-x))/(kw*CaO*(1-x)))
W=int(fun);
fplot(W,[0 1
But nothing comes out on the graph. I want to plot W on the Y-axis and x on the X-axis, between 0 and 1 (because it's a conversion in chemistry).
Does anyone know what I'm doing wrong?

KALYAN ACHARJYA

KALYAN ACHARJYA (view profile)

on 15 Jun 2019
Actually, at present I dont have Matlab,therfore unable test it pls show int(fun) expression?
Marina Gonzalez

Marina Gonzalez (view profile)

on 15 Jun 2019
Sure!
W =
(10621383255117913671*x)/6101500778987273584640000 - (2711395674095616*log(x - 1))/363677786528305625
Walter Roberson

Walter Roberson (view profile)

on 15 Jun 2019
In this calculation W is imaginary below 2.0007245246191665436401515314702

Answer by Star Strider

Star Strider (view profile)

on 15 Jun 2019

But nothing comes out on the graph.
The result of the int function is a constant. At best, you will get a straight line.
I am not certain what you want. You can get it to plot as a function of the upper limit of integration by creating a function from it:
syms x a
kw = 91371;
CaO= 1.81*10^(-4);
FaO= 0.1233;
K = 1.29;
fun = FaO*((1+K*CaO*(1-x))/(kw*CaO*(1-x)));
W(a) = int(fun, x, 0, a);
fplot(W,[0 1])