Matlab plots my equation wrong

x=-20:0.1:20;
f2=x.^10-1;
plot(x,f2)

I cant understand why it sketches my basic code wrong.

[Walter Roberson]

It looks right to me. You might have overlooked the "x 10^12" on the upper left of the y axis.

[Stephen23]

Why is it wrong (apart from that you cut off the multiplier from the top of the y-axis)?

What do you expect to get?

[Melih Aksoy]

was expecting to get graph of x^10-1 which is

[Stephen23]

"was expecting to get graph of x^10-1 which is"

That is exactly what you already have. Again, you are just ignoring the multiplier at the top of the y-axis. Set the y-limits to [-1,3] and you will see the part of the curve that you expect.

[Melih Aksoy]

I am sorry but i am really new at MATLAB. How can i set y-limits?

Answer 1

[Stephen23]

MATLAB has plotted exactly what you asked for, where the y-range ranges over:

>> x = -20:0.1:20;
>> y = x.^10-1;
>> max(y)
ans = 10239999999999
>> min(y)
ans = -1

Over that range of y-values I would not expect to be able to distinguish between 0 and -1, they will appear exactly the same on your monitor (unless you have a monitor with more than eleven trillion pixels vertically, in which case those two values will appear one pixel different from each other).

You can limit the plot's y-range if you want:

ylim([-1,3])

or reduce the x-domain:

x = -1.1:0.1:1.1;

[Melih Aksoy]

Thank you man! It's a big help.