matrix dimension must agree

I have been facing issues to get this equation to work out.

a = (5:0.1:20);
b = (15:0.2:40);
y = (30:0.5:40);

P = 1 + (cos(a/5)).*(sin(b/5))-((y.^2)/(a.*(b.^3)));

Answer 1

[madhan ravi]

a = linspace(5,20);
b = linspace(15,40);
y = linspace(30,40);

P = 1 + (cos(a/5)).*(sin(b/5))-((y.^2)./(a.*(b.^3)));