Solving an equation of 3 unknown variables by inputing 3 sets of data

Hello everyone,

I am a rookie in Matlab. This is my first routine.

I would like to solve a three variable equation (A, B, C) by inputing 3 sets of data (x1,y1 | x2,y2 | x3,y3).

The equation is y=A+Bx+C/x.

I would like the program to ask me for the 3 inputs, like :

Enter data set x1,y1 :

Enter data set x2,y2 :

Enter data set x3,y3 :

The calculation would be

y1=A+Bx1+C/x1

y2=A+Bx2+C/x2

y3=A+Bx3+C/x3

And then return A=....., B=....., C=.....,

Thank you in advance.

Dimitris

Answer 1

[Yongjian Feng]

Try it yourself first, and we can then help to improve your work. Your task can be broken down into the following subtask:

1. Reading user input: https://www.mathworks.com/help/matlab/ref/input.html
2. Solve equations: https://www.mathworks.com/help/symbolic/solve.html#d123e272541

Answer 2

[Dimitris Gkoutzamanis]

Thank you Feng! I think I did it:)

prompt = 'Enter x1: ';
x1 = input(prompt)
prompt = 'Enter y1: ';
y1 = input(prompt)
prompt = 'Enter x2: ';
x2 = input(prompt)
prompt = 'Enter y2: ';
y2 = input(prompt)
prompt = 'Enter x3: ';
x3 = input(prompt)
prompt = 'Enter y3: ';
y3 = input(prompt)

syms A B C
eqns = [A + B*x1 + C/x1 == y1, A + B*x2 + C/x2 == y2, A + B*x3 + C/x3 == y3];
S = solve(eqns,[A B C])