1. Function y = - x2 + X-1 how many intersections are there between image and X axis 3. The vertex coordinates of the function y = - 1 / 2 (x + 1) 2 + 2 are 4. According to the following conditions, find the analytic expression of quadratic function. (1) the image passes through points (1, - 2), (0, - 3), (- 1, - 6); (2) When x = 3, the function has a minimum value of 5 and passes through points (1,11); (3) The function image intersects the x-axis at two points (1 - √ 2,0) and (1 + √ 2,0), and intersects the y-axis at (0, - 2)

1. Function y = - x2 + X-1 how many intersections are there between image and X axis 3. The vertex coordinates of the function y = - 1 / 2 (x + 1) 2 + 2 are 4. According to the following conditions, find the analytic expression of quadratic function. (1) the image passes through points (1, - 2), (0, - 3), (- 1, - 6); (2) When x = 3, the function has a minimum value of 5 and passes through points (1,11); (3) The function image intersects the x-axis at two points (1 - √ 2,0) and (1 + √ 2,0), and intersects the y-axis at (0, - 2)

1. Look at the discriminant; 3. Use the formula (- B / 2a, (4ac-b & # 178;) / 4A); 4. (1) let y = ax & # 178; + BX + C, solve the system of linear equations of three variables; (2) let y = a (x-3) &# 178; + 5; (3) let y = a (x-1 + √ 2) (x-1 - √ 2)