How to plot two variables in a single function?

How do I create a plot that shows the variation of k with respect to x in the following function without actually rearranging it? y-a*x + sin(b*x^2) + k*m=0

Assume the remaining terms have fixed values.

 syms y a b k x
   b*x^2 - a*x + y + k*m == 0

>> a=2, b=3,y=4;
>> x= 1:0.5:5;
>> plot(x,m)

The above code results in the following message "Error using plot Conversion to double from sym is not possible."

Answer 1

[Walter Roberson]

Your line

     b*x^2 - a*x + y + k*m == 0

does not define anything. It creates an expression and prints the value of the expression to the screen, but it does not create any assignment.

Perhaps you want something like

     eqn = b*x^2 - a*x + y + k*m == 0;

and then later

    M = double( solve(subs(eqn), m) );
    plot(x, M)

Answer 2

[KSSV]

a=2, b=3,k=1:4;
x= 1:0.5:5;
X=zeros(length(k),length(x));
Y=zeros(length(k),length(x));
for i=1:length(k)
Y(i,:)= -b*x^2 +a*x-k(i)*m ;
end
plot(X,Y)

The above plots x,y for k = 1,2,3,4.