Course Content
Algebra 1
0/14
Algebra 2
0/16
Trigonometry 1
0/18
Coordinate Geometry of the Line
0/14
Probability 1
0/14
Geometry 1
0/6
Differential Calculus
0/10
Trigonometry 2
0/10
Sequences & Series
0/12
Statistics 1
0/9
Coordinate Geometry of the Circle
0/14
Algebra 3
0/16
Complex Numbers
0/12
Geometry 2
0/4
Integration
0/8
Differential Calculus Applications
0/8
Financial Maths
0/8
Length, Area & Volume
0/6
Probability 2
0/9
Functions
0/15
Statistics 2
0/4
Inferential Statistics
0/6
Digital Lessons

Knowledge Check Quiz

#### EXAMS.IE

##### De Moivre's Theorem

Hint

This is a cubic equation equation.

1 / 5

How many solutions are there to $$x^3=8$$?

Hint

$$(-2)^3=-8$$

2 / 5

$$-2$$ is a solution to $$x^3=8$$.

Hint

No other solutions can be found by inspection.

3 / 5

How many of the solutions to $$x^3=8$$ are purely real?

Hint

Purely real numbers are also complex.

4 / 5

How many of the solutions to $$x^3=8$$ are complex?

Hint

The answer can be determined by using the Conjugate Roots theorem.

5 / 5

If $$x=a+bi$$ is a solution to $$x^3=8$$, which of the following must also be a solution?