INTRODUCTION:
The value of the polynomial p(x) at x = a is p(a).
Zeroes of the polynomial p(x) can be found by equating p(x) to zero and solving the equation.
If for p(x) = ax2 + bx + c = 0, a ≠ 0; α and β are the zeroes, then
If α and β are the zeroes; then quadratic polynomial will be given by k [x2 – Sx + P]
where S = α +β and P = αβ k (≠0) is real.
The degree of a polynomial p(x) in x is the highest power of x in p(x)
(i) Polynomial with degree 1, of the form ax + b; a ≠ 0 is called linear polynomial.
(ii) Polynomial with degree 2, of the form ax² + bx + c; a ≠ 0 is called quadratic polynomial.
(iii) Polynomial with degree 3, of the form ax3 + bx2 + cx + d ; a ≠ 0 is called cubic polynomial.
For any polynomial y = f(x), the number of points on which the graph of y = f(x) intersects at x-axis is called the number of the zeroes of the polynomial and the x-coordinates of these points are called the zeroes of the polynomial y = f(x).
Polynomial with degree ‘n’ has maximum ‘n’ number of zeroes.
A constant polynomial has no zeroes.
Geometrical representation of a linear polynomial is always a straight line.
Geometrical representation of a quadratic polynomial is the graph of the shape either open upwards like ‘∪’ or open downwards like ‘∩’ according to a > 0 or a < 0. These curves are called Parabolas.
If α and β are the zeroes of the quadratic polynomial p(x) = ax2 + bx + c where a≠0 then
A quadratic polynomial p(x) with zeroes α and β is given by
p(x) = k [x2 – (α + β)x + αβ]
where k (≠0) is real.
Division Algorithm for Polynomials:
If p(x) and g(x) are any two polynomials where g(x) ≠ 0.
Then on dividing p(x) by g(x), we can find other two polynomials q(x) and r(x) such that
p(x) = g(x) x q(x) + r(x);
where deg. of r(x) < deg. of g(x)
or Dividend = (Divisor x Quotient) + Remainder
Note:
- If r(x) = 0, then g(x) will be a factor of p(x) otherwise not.
- If any real number ‘a’ is a zero of the polynomial p(x), then (x – a) will be a factor of p(x).