topic badge

3.04 Introduction to polynomials

Worksheet
Definition and parts of a polynomial
1

Determine whether the following are polynomials:

a

A \left( x \right) = 4 x^{\frac{1}{4}} + 2 x^{5} + 2

b

3 x^{3} + \dfrac{2}{x^{7}} - 1

c
2x^3+9x-4
d
9x^4+6x^2+\sqrt{x}+10
e
5x^4 - 9x^3 + 2x^2 + 11x
f
2x^5 - 60x^2 - \dfrac{1}{x}
2

Consider the expression x + 7 x^{6} - x^{9}.

a

How many terms are in the expression?

b

What are the coefficients of the terms?

3

True or false: The degree of a polynomial in x is the largest coefficient of any of the terms of the polynomial.

4

For each of the following polynomials:

i
Find the degree.
ii
Find the leading coefficient.
iii
Find the constant term.
a

P \left( x \right) = 2 x^{7} + 2 x^{5} + 2 x + 2

b

P \left(x\right) = 7 \sqrt{6} - \sqrt{5} x^{5} + 5

c

P \left( x \right) = \dfrac{x^{7}}{5} + \dfrac{x^{6}}{6} + 5

5

Is it possible for the graph of a polynomial function to have:

a

No x-intercepts?

b

No y-intercepts?

6

State whether the following functions have exactly two x-intercepts.

a

y = \left(x + 3\right)^{3}

b

y = \left(x + 6\right)^{2} \left(x + 5\right)

c

y = \left(x + 7\right) \left(x - 1\right) \left(x - 4\right)

d

y = x \left(x - 2\right) \left(x - 8\right)

7

Patricia claims she can graph a third-degree polynomial function with 3 turning points.

Is this possible or impossible?

8

Consider the function f \left( x \right) = x^{7} - 9 x^{3} - 2.

a

What is the maximum number of real zeros that the function can have?

b

What is the maximum number of x-intercepts that the graph of the function can have?

c

What is the maximum number of turning points that the graph of the function can have?

9

For the polynomial P(x)= 4 - \dfrac{7 x^{6}}{6}, find:

a

P(-1)

b

P(\sqrt{2})

c

P\left(\dfrac{1}{2}\right)

10

Consider the function f \left( x \right) = x^{4} - 7 x^{3} + 12 x^{2} + 4 x - 16. Determine whether the following is a zero of the function:

a

x=5

b

x=4

c

x=- 1

11

The polynomial P \left( x \right) = a x^{4} - 6 x^{2} + 2 x + b is a monic polynomial of degree 4, with a constant term of - 2.

a

Find the value of a.

b

Find the value of b.

Sketching polynomials
12

The following graphs are of polynomials of the form y=x^n. For each graph, determine whether n is even or odd:

a
-4
-3
-2
-1
1
2
3
4
x
-1
1
2
3
4
5
6
7
8
9
y
b
-4
-3
-2
-1
1
2
3
4
x
-4
-3
-2
-1
1
2
3
4
y
13

Consider the functions y = x^{2}, y = x^{4} and y=x^6.

a

Describe the general shape of the graph of each function.

b

Sketch the graph of y = x^{2}, y = x^{4} and y=x^6 on the same number plane.

c

Describe what happens to the graph of a function of the form y=x^{2n} as n increases.

14

Consider the functions y = x^{3}, y = x^{5}, and y=x^7.

a

Graph the three functions on the same number plane.

b

Describe what happens to the graph of a function of the form y=x^{2n+1} as n increases.

15

Consider the function y = - x^{7}.

a

As x approaches infinity, what happens to the corresponding y-values?

b

As x approaches negative infinity, what happens to the corresponding y-values?

c

Sketch the general shape of y = - x^{7}.

16

Consider y = x^{3} - 8.

a

Find the coordinates of the point of inflection on the curve.

b

Find the x-intercept of the curve.

c

Hence plot the curve y = x^{3} - 8.

17

For each of the following functions:

i

Find the x-intercept(s).

ii

Find the y-intercept(s).

iii

Plot the graph of the curve.

a

y = \left(x + 3\right) \left(x + 2\right) \left(x - 2\right)

b

y = \left(x - 2\right)^{2} \left(x + 5\right)

c

y = \left(x - 1\right) \left(x - 2\right) \left(x + 4\right) \left(x + 5\right)

d

y = - \left(x + 1\right) \left(x + 3\right) \left(x + 4\right) \left(x - 4\right)

e

y = \left(x - 2\right)^{2} \left(x + 3\right) \left(x - 1\right)

f

y = - \left(x - 3\right)^{2} \left(x + 1\right) \left(x - 2\right)

g

y = - \left(x - 3\right)^{2} \left(x + 2\right)^{2}

h

y = \left(x + 2\right)^{3} \left(x - 2\right)

18

For each of the following functions:

i

As x \to -\infty what does y approach?

ii

As x \to \infty what does y approach?

iii

Find the x-intercepts for this function

iv

Find the y-intercept of the function

v

Sketch the graph of the function.

a
y = x \left(x + 1\right) \left(x - 2\right) \left(x - 4\right)
b
y = - x \left(x + 2\right) \left(x - 2\right) \left(x - 3\right)
c
y = - x^{5} + x^{3}
19

Graph the function f \left( x \right) = x \left(x + 3\right) \left(x - 3\right).

20

Consider the polynomial function y = x^{4} - 4 x^{2}

a

Determine the leading coefficient.

b

Does the function rise or fall to the left?

c

Does the function rise or fall to the right?

d

Express the equation in factorised form.

e

Find the x-intercepts.

f

Find the y-intercept.

g

Sketch the graph of y = x^{4} - 4 x^{2}.

21

Consider the polynomial function y = x^{4} - x^{2}

a

Determine the leading coefficient.

b

Is the degree odd or even?

c

Does the function rise or fall to the left?

d

Does the function rise or fall to the right?

e

Hence, sketch the graph of y = x^{4} - x^{2}.

22

Sketch the graph of the function f \left( x \right) = 2 x^{4} - x^{2} + 2.

23

Consider the curve y = - \left(x - 1\right)^{2} \left(x^{2} - 9\right).

a

Find the x-intercept(s).

b

Find the y-intercept(s).

c

Determine whether the graph has y-axis symmetry, origin symmetry, or neither.

d

Plot the graph of the curve.

Applications
24

Find the equation for each of the following curves in factored form. Assume each curve is a monic cubic polynomial.

a
-4
-3
-2
-1
1
2
x
-4
-3
-2
-1
1
2
3
4
5
6
7
8
y
b
-3
-2
-1
1
2
x
-2
-1
1
2
3
4
5
6
7
8
9
y
25

Consider the graph of y = f \left( x \right):

a

What are the roots of y = f \left( x \right)?

b

Find the equation of f \left( x \right).

c

Solve the inequality f \left( x \right) \geq 0.

-1
1
2
3
4
5
6
7
8
x
-2
-1
1
2
3
4
5
6
y
Sign up to access Worksheet
Get full access to our content with a Mathspace account

Outcomes

MA11-1

uses algebraic and graphical techniques to solve, and where appropriate, compare alternative solutions to problems

What is Mathspace

About Mathspace