From our earlier observation about the shape of the graph of y = ax2 + bx + c, (a not equal to 0)

the following three cases arise.

Case (i) :

Here, the graph cuts X-axis at two distinct points A and A¢ . In this case, the x-coordinates of A and A¢ are the Two zeroes of the quadratic polynomial ax2+bx +c . The parabola opens either upward or downward.


Case (ii) :

Here, the graph touches X-axis at exactly one point, i.e., at two coincident points. So, the two points A and A¢ of Case (i) coincide here to become one point A.

In this case, the x-coordinate of A is the only zero for the quadratic pol




page no:58

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