Polynomials-Types, Graphs, Factor and Remainder theorem
Types of polynomials :
i) Constant polynomial : A polynomial having degree ‘0’ is called constant polynomial
For ex: \(
\sqrt {11} ,3,-7/8,1
\) and so on
Degree of constant polynomial ‘0’ because \(
\frac{{ - 7}}
{8} = \frac{{ - 7}}
{8} \times 1 = \frac{{ - 7}}
{8}x^o
\)
ii) Zero polynomial : ‘0’ is called Zero polynomial. We can’t define degree of zero polynomial
\(
\because \,\,\,\,\,\,0 = 0.x^n + 0.x^{n - 1} + .....
\)
as ‘n’ may be any number. We can’t say degree
\(\therefore\)Degree is not defined
iii) Linear polynomial : A polynomial with degree one is called Linear polynomial, Graph of a linear polynomial is a straight line.
For ex:\(
11x,\,\,\frac{{3x}}
{2},\,\,\frac{{\sqrt 2 }}
{{x^{ - 1} }}
\) \(
3x + 1,\,5p - 3,\,6q - \frac{{13}}
{2}
\) so on…
iv) Quadratic polynomial :A polynomial of degree ‘2’ is called Quadratic polynomial
For ex:\(
3x^2 + 5x + 7,\,x^2 - 5x + 6,\,ax^2 + bx + c(a \ne 0)
\)
Graph of Quadratic polynomial is parabola .
v) Cubic polynomial: A polynomial of degree ‘3’ is called cubic polynomial
For ex : \(
3x^3 + 7x^2 + x + 1,\,9x^3 + 11x^2 + 20x - 5,\,ax^3 + bx^2 + cx + d(a \ne 0)
\) and so on.
v) Biquadratic polynomial : A polynomial of degree ‘4’ is called as a bi-quadratic polynomial. It is also known as a bi-quadratic polynomial
For ex :\(
5x^4 + 6x^3 + 7x^2 - 11x + 1,\,\sqrt {20} x^4 + 11x^3 - 6x + 1,
\)
\(
ax^4 + bx^3 + cx^2 + dx + e(a \ne 0)
\)
11. Value of a polynomial : If p(x) is a polynomial at x = K. The value of polynomial is defined as p(K), it may be zero or any non-zero real number
For ex : 1) For a polynomial \(
p(x) = x^2 - 5x + 6
\) at x = 2, \(
p(2) = 2^2 - 5.2 + 6 = 0
\)
\(
\therefore p(2) = 0
\)
2) For a polynomial \(
p(x) = 8x^3 - 7x^2 + 6x - 5
\) at x = 1
\(
p(1) = 8.1^3 - 7.1^2 + 6.1 - 5
\)
\(
= 8 - 7 + 6 - 5 = 2
\)
\(
p(1) = 2 \ne 0
\)