We know that a real number k is a zero of the polynomial p(x) if p(k) = 0 in a geometrical way.
The x-coordinate of the point, where the graph of a polynomial intersect the x-axis is called the zero of the polynomial.
An nth - degree polynomial intersects the x-axis of n points and therefore, has a maximum of n zeros in geometrical graph
In a quadratic polynomial ax2 + bx +c,
If a>0, then the graph is a parabola that open upwards.
If a<0, then the graph is a parabola that open downwards.
Special case to the zeroes of a polynomial in geometrical meaning
In a geometrical way the evaluation of zeroes with polynomial evaluation of the equation in geometrical meaning is follows
Case (i) :
Here, the graph cuts x-axis at two distinct points A and A′.
The x-coordinates of A and A′ are the two zeroes of the quadratic polynomial ax2 + bx + c in this case is shown in the following figure
![](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_vj5tjJk63N57QHc_nYcyT8LXhl16ekDWb2fPhYvzvoNDy_Y9jGSm4-yGeIvFJOg8jyuOA61RvrsSCEWTqo3sWDAsGuHpu31cOJOB5vXJJFU4sx5CxwOyWIQo2Q=s0-d)
Case (ii) :
The graph given here cuts the 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 is shown in the following figure.
![](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_vc8ThpaCtS4gVWyN6Wo7FL_Y0CVTx5kcLE8WAOrKXj_TnPP1qMpowxzY7CXcNMYq3v31tPopP5MRzBcEkb1UuGacPOp5Q6fsPFaDRs4u58WJUolpqSTKxC6k4M=s0-d)
The x-coordinates of the A is the only zero for the quadratic polynomial ax2 + bx + c in this case.
So, the quadratic polynomial ax2 + bx + c has no zero in this case.
So, you can see geometrically that a quadratic polynomial can have either two distinct zeroes or two equal zeroes (i.e., one zero), or no zero. This also refers that the polynomial of degree 2 has at-most two zeroes is shown in the following figure.
The x-coordinate of the point, where the graph of a polynomial intersect the x-axis is called the zero of the polynomial.
An nth - degree polynomial intersects the x-axis of n points and therefore, has a maximum of n zeros in geometrical graph
In a quadratic polynomial ax2 + bx +c,
If a>0, then the graph is a parabola that open upwards.
If a<0, then the graph is a parabola that open downwards.
Special case to the zeroes of a polynomial in geometrical meaning
In a geometrical way the evaluation of zeroes with polynomial evaluation of the equation in geometrical meaning is follows
Case (i) :
Here, the graph cuts x-axis at two distinct points A and A′.
The x-coordinates of A and A′ are the two zeroes of the quadratic polynomial ax2 + bx + c in this case is shown in the following figure
Case (ii) :
The graph given here cuts the 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 is shown in the following figure.
The x-coordinates of the A is the only zero for the quadratic polynomial ax2 + bx + c in this case.
No zero case
The graph given here is either completely above the x-axis or completely below the x-axis. So, it does not cut the x-axis at any pointSo, the quadratic polynomial ax2 + bx + c has no zero in this case.
So, you can see geometrically that a quadratic polynomial can have either two distinct zeroes or two equal zeroes (i.e., one zero), or no zero. This also refers that the polynomial of degree 2 has at-most two zeroes is shown in the following figure.