This is a Numerical Analysis programSolutionSolution The mf

This is a Numerical Analysis program

Solution

Solution :

The m-file that we might use to accomplish this task is very simple:

function x = rqe(a,b,c)
x(1) = (-b + sqrt(b^2 - 4 * a * c))/(2*a);
x(2) = (-b - sqrt(b^2 - 4 * a * c))/(2*a);

We enter the coefficients as parameters when we call the function. We assign to variables x(1) and x(2) the calculated values using the formula, and the returning result x is a vector containing x(1) and x(2).

We could use the following Matlab code instead, to return two separate variables:

function [x,y] = rqe2(a,b,c)
x = (-b + sqrt(b^2 - 4 * a * c))/(2*a);
y = (-b - sqrt(b^2 - 4 * a * c))/(2*a);

If we want to compute the roots of the following expression:

2x² + x - 1 = 0

We can call our function (first code) like this:

x = rqe(2, 1, -1)

and we get from Matlab:

x =     0.5000   -1.0000

We can call our second function (second code above) like this:

[m, n] = rqe2(2, 1, -1)

and we get from Matlab:

m =     0.5000

n =     -1

OR

Solve the function you can

>> [x]=solve(\'a*x^2+b*x+c=0\',\'x\')
x =
-(b + (b^2 - 4*a*c)^(1/2))/(2*a)
-(b - (b^2 - 4*a*c)^(1/2))/(2*a)

For example:
>> [x]=solve(\'5*x^2+10*x+3=0\')
x =
- 10^(1/2)/5 - 1
10^(1/2)/5 - 1


>> [x]=solve(\'x^2-x-6=0\')

x =
-2
3