(1,-2) | (2,-2) | (-1,-2) | (-2,-2) |
(1,-1) | (2,-1) | (-1,-1) | (-2,-1) |
(1,2) | (2,2) | (-1,2) | (-2,2) |
(1,1) | (2,1) | (-1,1) | (-2,1) |
∵关于x的方程x2+bx+c=0有实数解,即 b2-4c≥0,
∴关于x的方程x2+bx+c=0有实数解的有(1,-1),(1,-2),(2,1),(2,-1),(2,-2),(-1,-1),(-1,-2),(-2,1),(-2,-1),(-2,-2)共10种情况,
∴关于x的方程x2+bx+c=0有实数解的概率为:
10 |
16 |
5 |
8 |
(2)(1)中方程有两个相等实数解的有(-2,1),(2,1),
∴(1)中方程有两个相等实数解的概率为:
2 |
16 |
1 |
8 |