How to find critical points of equations in Matlab?

In Matlab, we use meshgrid

a double for loop instead to increase speed, especially when the number of iterations is large.

In my application I am using meshgrid

matrix to find the critical point.

syms x
a=0.1:5
b=0.1:5
[A,B]=meshgrid(a,b)
y=A*x^2+B*x+B
y_deriv=diff(y,x)
solution=solve(y_deriv==0,x)

      

        
        
        
      

    

However, this gives me

Warning: 25 equations in 1 variables. 
> In C:\Program Files\MATLAB\R2013b\toolbox\symbolic\symbolic\symengine.p>symengine at 56
  In mupadengine.mupadengine>mupadengine.evalin at 97
  In mupadengine.mupadengine>mupadengine.feval at 150
  In solve at 170 
Warning: Explicit solution could not be found. 
> In solve at 179 

solution =

[ empty sym ]

      

        
        
        
      

    

What I wanted to do was:

solve(y_deriv(1)==0,x)

      

        
        
        
      

    

and

solve(y_deriv(2)==0,x)

      

        
        
        
      

    

... etc.

I could do it in a loop, but I don't want to. Is there any step by step solution for a sane solution in Matlab?

Update:

I think y_deriv

gives me:

[ x/5 + 1/10,  (11*x)/5 + 1/10,  (21*x)/5 + 1/10,  (31*x)/5 + 1/10,  (41*x)/5 + 1/10]
[ x/5 + 11/10, (11*x)/5 + 11/10, (21*x)/5 + 11/10, (31*x)/5 + 11/10, (41*x)/5 + 11/10]
[ x/5 + 21/10, (11*x)/5 + 21/10, (21*x)/5 + 21/10, (31*x)/5 + 21/10, (41*x)/5 + 21/10]
[ x/5 + 31/10, (11*x)/5 + 31/10, (21*x)/5 + 31/10, (31*x)/5 + 31/10, (41*x)/5 + 31/10]
[ x/5 + 41/10, (11*x)/5 + 41/10, (21*x)/5 + 41/10, (31*x)/5 + 41/10, (41*x)/5 + 41/10]

      

        
        
        
      

    

I want to solve the x/5+1/10==0

, x/5+11/10==0

, x/5+21/10==0

, and etc ... for all elements in the matrix.