Hyperbolic tangent(without Inbuilt)

%hyperbolic tangent function without using inbuilt func
x = -10:0.01:10;
a = input('Enter the slope parameter')
y = (exp(a.*(x))-exp(-a.*(x)))./(exp(a.*(x))+exp(-a.*(x)));
plot(x,y);
xlabel('x')
ylabel('y')
grid on