Trigonometry Examples

Graph f(x)=cos(2pix)
Step 1
Use the form to find the variables used to find the amplitude, period, phase shift, and vertical shift.
Step 2
Find the amplitude .
Amplitude:
Step 3
Find the period of .
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Step 3.1
The period of the function can be calculated using .
Step 3.2
Replace with in the formula for period.
Step 3.3
is approximately which is positive so remove the absolute value
Step 3.4
Cancel the common factor of .
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Step 3.4.1
Cancel the common factor.
Step 3.4.2
Rewrite the expression.
Step 3.5
Cancel the common factor of .
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Step 3.5.1
Cancel the common factor.
Step 3.5.2
Rewrite the expression.
Step 4
Find the phase shift using the formula .
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Step 4.1
The phase shift of the function can be calculated from .
Phase Shift:
Step 4.2
Replace the values of and in the equation for phase shift.
Phase Shift:
Step 4.3
Cancel the common factor of and .
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Step 4.3.1
Factor out of .
Phase Shift:
Step 4.3.2
Cancel the common factors.
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Step 4.3.2.1
Factor out of .
Phase Shift:
Step 4.3.2.2
Cancel the common factor.
Phase Shift:
Step 4.3.2.3
Rewrite the expression.
Phase Shift:
Phase Shift:
Phase Shift:
Step 4.4
Divide by .
Phase Shift:
Phase Shift:
Step 5
List the properties of the trigonometric function.
Amplitude:
Period:
Phase Shift: None
Vertical Shift: None
Step 6
Select a few points to graph.
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Step 6.1
Find the point at .
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Step 6.1.1
Replace the variable with in the expression.
Step 6.1.2
Simplify the result.
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Step 6.1.2.1
Multiply .
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Step 6.1.2.1.1
Multiply by .
Step 6.1.2.1.2
Multiply by .
Step 6.1.2.2
The exact value of is .
Step 6.1.2.3
The final answer is .
Step 6.2
Find the point at .
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Step 6.2.1
Replace the variable with in the expression.
Step 6.2.2
Simplify the result.
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Step 6.2.2.1
Cancel the common factor of .
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Step 6.2.2.1.1
Factor out of .
Step 6.2.2.1.2
Factor out of .
Step 6.2.2.1.3
Cancel the common factor.
Step 6.2.2.1.4
Rewrite the expression.
Step 6.2.2.2
Combine and .
Step 6.2.2.3
The exact value of is .
Step 6.2.2.4
The final answer is .
Step 6.3
Find the point at .
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Step 6.3.1
Replace the variable with in the expression.
Step 6.3.2
Simplify the result.
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Step 6.3.2.1
Cancel the common factor of .
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Step 6.3.2.1.1
Factor out of .
Step 6.3.2.1.2
Cancel the common factor.
Step 6.3.2.1.3
Rewrite the expression.
Step 6.3.2.2
Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because cosine is negative in the second quadrant.
Step 6.3.2.3
The exact value of is .
Step 6.3.2.4
Multiply by .
Step 6.3.2.5
The final answer is .
Step 6.4
Find the point at .
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Step 6.4.1
Replace the variable with in the expression.
Step 6.4.2
Simplify the result.
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Step 6.4.2.1
Cancel the common factor of .
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Step 6.4.2.1.1
Factor out of .
Step 6.4.2.1.2
Factor out of .
Step 6.4.2.1.3
Cancel the common factor.
Step 6.4.2.1.4
Rewrite the expression.
Step 6.4.2.2
Combine and .
Step 6.4.2.3
Move to the left of .
Step 6.4.2.4
Apply the reference angle by finding the angle with equivalent trig values in the first quadrant.
Step 6.4.2.5
The exact value of is .
Step 6.4.2.6
The final answer is .
Step 6.5
Find the point at .
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Step 6.5.1
Replace the variable with in the expression.
Step 6.5.2
Simplify the result.
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Step 6.5.2.1
Multiply by .
Step 6.5.2.2
Subtract full rotations of until the angle is greater than or equal to and less than .
Step 6.5.2.3
The exact value of is .
Step 6.5.2.4
The final answer is .
Step 6.6
List the points in a table.
Step 7
The trig function can be graphed using the amplitude, period, phase shift, vertical shift, and the points.
Amplitude:
Period:
Phase Shift: None
Vertical Shift: None
Step 8