How to solve for all 5 values of x?

T= (473:50:673);

K=exp(21.225+(9143.6./T)-(7.492*log(T))+((4.076*10^-3)*(T))-(7.161*10^-8).*(T).^2);

syms x

function

eqn= ((100*x-2*x^2)/(1625-115*x+2*x^2))==K(1)*(5476);

solx= solve(eqn,x)

I want to solve for all the different values of x (there should be 5) using each different value of K. I tried just using K as a variable but gave me an error so I was going to do each individual K using K(1), K(2), etc. but it gives me a funciton instead of a value. please help!

Answer 1

[Star Strider]

I would use a loop:

T= (473:50:673);
K=exp(21.225+(9143.6./T)-(7.492*log(T))+((4.076*10^-3)*(T))-(7.161*10^-8).*(T).^2);

syms x
for m = 1:numel(K)
    eqn= ((100*x-2*x^2)/(1625-115*x+2*x^2))==K(m)*(5476);
    solx(:,m) = vpasolve(eqn,x);
end

to store the results as columns of ‘solx’.

If you want to use them in numeric applications, use:

soln = double(solx);

[Mary Jean Savitsky]

thats perfect! the only problem is if I run it and display the solution, it gives it 5 times repeated. Is there anyway I can get it to just show once?

[Star Strider]

Thank you!

I don’t understand. The ‘solx’ and ‘soln’ matrices are (2x5), with every column being a solution for a different value of ‘T’. (This is true in R2020a, however it should be the same in recent earlier releases as well.)

To plot them:

figure
plot(T, soln)
grid

.