Log display problem semilogx

Hi i want to show graph with log scale on x . this is my code:

a=5;

b=2;

x=0.0001:1000000;

y=@(x) ax+b;

figure

semilogx(x,y)

hold off

and this is my error:

Error using semilogx

Invalid data argument.

Error in Untitled1 (line 6)

semilogx(x,y)

i read how use semilogx and have no idea where i make mistake

Answer 1

[KALYAN ACHARJYA]

a=5;
b=2;
x=0.0001:1000000;
y=a*x+b;
figure
semilogx(x,y)