Question 36342: I asked this a few days ago but didn't get an answer. Can someone help me with this please?
When using the quadratic formula to solve a quadratic equation ax2 + bx + c = 0, the discriminant is b2 - 4ac. This discriminant can be positive, zero, or negative. (When the discriminate is negative, then we have the square root of a negative number. This is called an imaginary number, sqrt(-1) = i. )
Explain what the value of the discriminant means to the graph of y = ax2 + bx + c. Hint: Chose values of a, b and c to create a particular discriminant. Then, graph the corresponding equation. In the real world, where might these imaginary numbers be used?
Answer by ilana(307)   (Show Source):
You can put this solution on YOUR website! When the descriminant is positive, the parabola is either like a U with the vertex below the x-axis, or like an upside-down U with the vertex above the x-axis (so either way, the parabola intersects the x-axis at 2 points). When the descriminant is 0, the vertex is on the x-axis (like y=x^2), and when the descriminant is negative it never touches the x-axis. So it either starts above and continues up or starts below and continues down (like y=x^2+3 or y=-x^2-3).
I believe that's part of what the question is looking for.
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