All Algebra II Resources
Example Questions
Example Question #161 : Imaginary Numbers
Write the complex number in polar form, where polar form expresses the result in terms of a distance from the origin on the complex plane and an angle from the positive -axis, , measured in radians.
To see what the polar form of the number is, it helps to draw it on a graph, where the horizontal axis is the imaginary part and the vertical axis the real part. This is called the complex plane.
To find the angle , we can find its supplementary angle and subtract it from radians, so .
Using trigonometric ratios, and .
Then .
To find the distance , we need to find the distance from the origin to the point . Using the Pythagorean Theorem to find the hypotenuse , or .
Example Question #2 : Graphing Functions With Complex Numbers
Where does fall on the number line?
To the right of 0
To the left of 0
At 0
Cannot be determined
To the left of 0
Imaginary numbers do not fall on the number line by definition, since they are not real numbers. However, although i is an imaginary number equal to the square root of -1, is a real number since . Therefore, . Negative numbers fall to the left of 0 on a number line.
Example Question #2 : Graphing Functions With Complex Numbers
Which complex number does this graph represent?
Real numbers are represented by the x-axis, and imaginary numbers are represented by the y-axis.
In complex numbers of the form , a represents the real portion of the number and b represents the imaginary portion of the number. To graph on a plane in which real numbers are represented by the x-axis and imaginary numbers are represented by the y-axis, place a point a units right of the origin and b units above the origin. The graph shows a point 2 units right and 3 units above the origin, so the complex number represented is .
Example Question #6 : Graphing Functions With Complex Numbers
Which complex number does this graph represent?
Real numbers are represented by the x-axis, and imaginary numbers are represented by the y-axis.
In complex numbers of the form , a represents the real portion of the number and b represents the imaginary portion of the number. To graph on a plane in which real numbers are represented by the x-axis and imaginary numbers are represented by the y-axis, place a point a units right of the origin and b units above the origin. The graph shows a point 5 units left and 2 units below the origin, so the complex number represented is .
Example Question #3 : Graphing Functions With Complex Numbers
Which of the following represents the real component of the complex number ?
In complex numbers of the form , a represents the real portion of the number and b represents the imaginary portion of the number. In the complex number , and .
Example Question #4 : Graphing Functions With Complex Numbers
Which of the following represents the imaginary component of the complex number -3 + ki, in which k is a constant?
In complex numbers of the form , represents the real portion of the number and represents the imaginary portion of the number. In the complex number , and
Example Question #9 : Graphing Functions With Complex Numbers
Which complex number does this graph represent?
Real numbers are represented by the x-axis, and imaginary numbers are represented by the y-axis.
In complex numbers of the form , a represents the real portion of the number and b represents the imaginary portion of the number. To graph on a plane in which real numbers are represented by the x-axis and imaginary numbers are represented by the y-axis, place a point a units right of the origin and b units above the origin. The graph shows a point 4 units right and 7 units below the origin, so the complex number represented is .
Example Question #1 : Graphing Functions With Complex Numbers
Which complex number does this graph represent?
Real numbers are represented by the x-axis, and imaginary numbers are represented by the y-axis.
In complex numbers of the form , a represents the real portion of the number and b represents the imaginary portion of the number. To graph on a plane in which real numbers are represented by the x-axis and imaginary numbers are represented by the y-axis, place a point a units right of the origin and b units above the origin. The graph shows a point 8 units left and 1 unit above the origin, so the complex number represented is .
Example Question #1 : Absolute Value
Solve the following absolute value inequality:
To solve this inequality, it is best to break it up into two separate inequalities to eliminate the absolute value function:
or .
Then, solve each one separately:
Combining these solutions gives:
Example Question #1 : Solving Absolute Value Equations
Solve the inequality:
(no solution)
(no solution)
The inequality compares an absolute value function with a negative integer. Since the absolute value of any real number is greater than or equal to 0, it can never be less than a negative number. Therefore, can never happen. There is no solution.