Why I cant see plot line by plot?

[mtan (Modong Tan)]

Hello, I am beginner of mathematica.
Today I tried to test plot function and I couldn’t see my plot .

How can I see that?

[mtan (Modong Tan)]

Eventually, the problem was resolved.

f[t_] := t^2
Plot[f[t], {t, -2, 2}]

[22padrinos (Luis Ledesma)]

When I read your comment i stayed with the next question, why does your chart is different from a parable", I did it with the following code, and indeed i graph a parable, i am showing you what I did.

[mtan (Modong Tan)]

Hello luis and thanks for your reply,

I posted wrong graph image when I tested Piecewise function (Piecewise: Function defined in pieces for different conditions—Wolfram Documentation).

Thank you for pointing out the mistake

f[t_] := Piecewise[{{t^2, t < 0}, {t, t > 0}}]

Plot[f[t], {t, -2, 2}]