Question

Without drawing the graph of the equation, determine how many points the parabola has in common with the x-axis and whether its vertex lies above, on, or below the x-axis.

y = –2x(2) + x + 3

(Points : 4)
1 point in common; vertex on x-axis
2 points in common; vertex below x-axis
2 points in common; vertex above x-axis
no points in common; vertex below x-axis

Answer 1

First compute the discriminant\[D = b^2-4ac \]

Answer 2

how

Answer 3

The quadratic equation is y = -2x^2 + x + 3
Compare it with the standard equation y = ax^2 + bx + c
Hence get the values of a, b and c.
For example a = -2 then b = ? and c = ?

Answer 4

Did you get that