wayground logo

Free Printable Worksheets

NEW

Font size

S
M
L
XL
Worksheets

Complex Roots of Polynomials

Total questions: 28

Worksheet time: 2hrs 13mins

Name
Class
Date
1.
Use the Complex Conjugate Root Theorem to state another complex solution. Given that 3+5i is a root. 
a)
-3+5i
b)
-3-5i
c)
-5i
d)
3-5i
2.
Use the Complex Conjugate Root Theorem to state another complex solution. Given that -7i is a root. 
a)
7i
b)
-7i+1
c)
1-7i
d)
1+7i
3.
What is the total number of roots for the following equation?
ax5+ bx4+ cx3+ dx2+ ex+ f = y
a)
This equation has 2 roots.
b)
This equation has 4 roots.
c)
This equation has 5 roots.
d)
This equation has no roots.
4.
Which of these is a possible root of the polynomials?
x3 - 6x2 - x + 30
a)
0
b)
4
c)
-9
d)
-15
5.
What is another way to say "where a function crosses the x-axis"?
a)
x-intercept
b)
zero
c)
root
d)
all of these.
6.

Write a polynomial with roots at 2 and 3-2i in standard form.

a)

x3 - 7x2 + 25x - 21

b)

x3 - 8x2 + 25x - 26

c)

- 8x2 - 26

d)

x2 + 6ix - 4i

7.
What is the degree of the polynomial:
f(x) = -4x + 5x3 - 2x2
a)
Degree 2
b)
Degree 3
c)
Degree 4
d)
Degree 5
8.
Identify the degree of the polynomial and the sign of the leading coefficient 
a)
Leading Coefficient Positive
Degree - Even
b)
Leading Coefficient Positive
Degree - Odd
c)
Leading Coefficient Negative
Degree - Even
d)
Leading Coefficient Negative
Degree - Odd
9.

Find the polynomial equation with given zeros.

a)

x3-x2+4x+4

b)

x3+x2+4x+4

c)

x3-x2-4x+4

d)

x3+x2+4x-4

10.
What does i2 equal to?
a)
1
b)
-1
c)
i
d)
-i
11.

What is the conjugate of -8i?

a)

-8i

b)

8i

c)

8

d)

-8

12.

What is the complex conjugate of 3 + √3?

a)

3 - √3

b)

-3 - √3

c)

3 + √3

d)

-3 + √3

13.
All imaginary roots comes in pairs.
a)
True
b)
False
14.

Write the polynomial in standard form given the following zeros. x = -2, 1, 4

a)

f(x) = (x+2)(x-1)(x-4)

b)

f(x) =x3 - 3x2 - 6x + 8

c)

f(x) = x3 + 8

d)

f(x) = x3 - 3x2 + 8

15.

Which of the following would be the correct factored form with roots 2, 5i, and 6?

a)

(x-6)(x-2)(x+5i)(x-5i)

b)

(x+6)(x+2)(x+5i)

c)

(x-6)(x-2)(x-5i)

d)

(x+6)(x+2)(x-5i)

16.

If a+bi is a root of a polynomial, then _______ is also a root.

a)

i2

b)

a-bi

c)

a+bi

d)

-i2

17.
Use the Complex Conjugate Root Theorem to state another complex solution. Given that -2-5i is a root. 
a)
-2-5i
b)
-2+5i
c)
2+5i
d)
5i
18.
Find a polynomial function of degree 3 with zeros 3i and -2.
a)
P(x) = x3+2x2+9x+11
b)
P(x) = x3-2x2+9x+18
c)
P(x) = x3+2x2+9x+18
d)
P(x) = x2-3ix+2x-6i
19.

Write a polynomial function of least degree with integral coefficients that has the given zeros.

-1, 5, -3+2i

a)

x4+2x3-16x2-82x-69

b)

x4+7x3-16x2-82x-65

c)

x4+2x3-16x2-82x-65

d)

x4+2x3-16x2-82x-68

20.

Write a polynomial function of least degree with integral coefficients that has the given zeros.

5, -2i

a)

x3-5x2+4x-20

b)

x3-5x2+4x-23

c)

x3-5x2+4x-19

d)

x3-10x2+4x-20

21.

Factor each polynomial and state the roots. x412x2+32=0x^4-12x^2+32=0  

a)

{2,  22}\left\{2,\ \ 2\sqrt{2}\right\}  

b)

{2, 2, 22}\left\{2,\ -2,\ 2\sqrt{2}\right\}  

c)

{2, 2, 8}\left\{2,\ -2,\ \sqrt{8}\right\}  

d)

{2,2, 22,22}\left\{2,-2,\ 2\sqrt{2},-2\sqrt{2}\right\}  

22.

Write a polynomial function of least degree in standard form that has the follow roots.
3, 5-3,\ \sqrt{5}  

a)

f(x)=(x+3)(x25)f\left(x\right)=\left(x+3\right)\left(x^2-5\right)  

b)

f(x)=(x3)(x5)f\left(x\right)=\left(x-3\right)\left(x-\sqrt{5}\right)  

c)

f(x)=x3+3x25x15f\left(x\right)=x^3+3x^2-5x-15  

d)

f(x)=x33x2+5x+15f\left(x\right)=x^3-3x^2+5x+15  

23.

Find all exact roots.  f(x)=x3+7x27x57f\left(x\right)=x^3+7x^2-7x-57  

a)

{3, 2 ± 23}\left\{-3,\ -2\ \pm\ \sqrt{23}\right\}  

b)

{3, 2, ±23}\left\{-3,\ -2,\ \pm\sqrt{23}\right\}  

c)

{3, 3, 2, 2, ±23}\left\{3,\ -3,\ 2,\ -2,\ \pm\sqrt{23}\right\}  

d)

{3, ±23}\left\{-3,\ \pm\sqrt{23}\right\}  

24.

What is the conjugate of 2 + √3

a)

2 + √3

b)

2 - √3

c)

-2 + √3

d)

-2 - √3

25.

All zeros containing a square root sign comes in pairs.

a)

True

b)

False

26.

What is the complex conjugate of 3 + √3?

a)

3 - √3

b)

-3 - √3

c)

3 + √3

d)

-3 + √3

27.

Given the polynomial below, how many roots will it have?
y=x3+5x29x2y=x^3+5x^2-9x-2  

a)

2

b)

1

c)

3

d)

0

28.
What is the degree of the following polynomial that has 4 real roots and 2 complex roots?
a)
4
b)
2
c)
8
d)
6