Vẽ đồ thị các hàm số sau:
a) y = –x2;
b) y = x2;
c) y = \(\frac{1}{5}\)x2;
d) y = –0,2x2.
a) y = 2x2;
b) y = –4x2;
c) y = = 5x2;
d) y = –2,5x2;
e) y = \(\frac{7}{2}\)x2;
g) y = \( - \frac{8}{5}\)x2.