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Example Questions
Example Question #4 : Express Complex Numbers In Polar Form
What is the polar form of the complex number ?
The correct answer is
The polar form of a complex number is where is the modulus of the complex number and is the angle in radians between the real axis and the line that passes through ( and ). We can solve for and easily for the complex number :
which gives us
Example Question #5 : Express Complex Numbers In Polar Form
Express the complex number in polar form:
Remember that the standard form of a complex number is: , which can be rewritten in polar form as: .
To find r, we must find the length of the line by using the Pythagorean theorem:
To find , we can use the equation
Note that this value is in radians, NOT degrees.
Thus, the polar form of this equation can be written as
Example Question #6 : Express Complex Numbers In Polar Form
Express this complex number in polar form.
None of these answers are correct.
Given these identities, first solve for and . The polar form of a complex number is:
at (because the original point, (1,1) is in Quadrant 1)
Therefore...
Example Question #501 : Pre Calculus
Convert to polar form:
First, find the radius :
Then find the angle, thinking of the imaginary part as the height and the radius as the hypotenuse of a right triangle:
according to the calculator.
We can get the positive coterminal angle by adding :
The polar form is
Example Question #3 : Express Complex Numbers In Polar Form
Convert to polar form:
First find the radius, :
Now find the angle, thinking of the imaginary part as the height and the radius as the hypotenuse of a right triangle:
according to the calculator.
This is an appropriate angle to stay with since this number should be in quadrant I.
The complex number in polar form is
Example Question #1 : Express Complex Numbers In Polar Form
Convert the complex number to polar form
First find :
Now find the angle. Consider the imaginary part to be the height of a right triangle with hypotenuse .
according to the calculator.
What the calculator does not know is that this angle is actually located in quadrant II, since the real part is negative and the imaginary part is positive.
To find the angle in quadrant II whose sine is also , subtract from :
The complex number in polar form is
Example Question #1 : Convert Polar Coordinates To Rectangular Coordinates
Convert the polar coordinates to rectangular coordinates:
To convert polar coordinates to rectangular coordinates ,
Using the information given in the question,
The rectangular coordinates are
Example Question #1 : Determine The Polar Equation Of A Graph
Which polar equation would produce this graph?
This is the graph of a cardiod. Based on its orientation where the cusp [pointy part] is on the y-axis, it is a sine and not cosine function. The x-intercepts are at , so the first number must be 2. Since vertically the graph goes from 0 to 4, the second number must be 2, because and .
Example Question #2 : Determine The Polar Equation Of A Graph
Give the polar equation for this graph:
This graph shows a rose curve with an odd number of petals.
This means that the equation will be in the form , where represents the length of the "petals" and represents the number of petals.
There are 5 petals of length 7.
Example Question #3 : Determine The Polar Equation Of A Graph
Which polar equation would produce this graph?
This graph shows a rose curve with an even number of petals. The first petal also intersects with the x-axis. This means that the equation will be in the form where is the length of each petal, and is half the number of petals. (Note that for an odd number of petals, the rose curve will have exactly petals). In this case, the petals have length 5, and there are 8 of them [half of 8 is 4].
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