Algebra Examples

Graph y=cos(theta/4+pi/4)-2
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 using the formula .
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Step 3.1
Find the period of .
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Step 3.1.1
The period of the function can be calculated using .
Step 3.1.2
Replace with in the formula for period.
Step 3.1.3
is approximately which is positive so remove the absolute value
Step 3.1.4
Multiply the numerator by the reciprocal of the denominator.
Step 3.1.5
Multiply by .
Step 3.2
Find the period of .
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Step 3.2.1
The period of the function can be calculated using .
Step 3.2.2
Replace with in the formula for period.
Step 3.2.3
is approximately which is positive so remove the absolute value
Step 3.2.4
Multiply the numerator by the reciprocal of the denominator.
Step 3.2.5
Multiply by .
Step 3.3
The period of addition/subtraction of trig functions is the maximum of the individual periods.
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
Multiply the numerator by the reciprocal of the denominator.
Phase Shift:
Step 4.4
Cancel the common factor of .
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Step 4.4.1
Move the leading negative in into the numerator.
Phase Shift:
Step 4.4.2
Cancel the common factor.
Phase Shift:
Step 4.4.3
Rewrite the expression.
Phase Shift:
Phase Shift:
Phase Shift:
Step 5
List the properties of the trigonometric function.
Amplitude:
Period:
Phase Shift: ( to the left)
Vertical Shift:
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
Simplify each term.
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Step 6.1.2.1.1
Combine the numerators over the common denominator.
Step 6.1.2.1.2
Add and .
Step 6.1.2.1.3
Divide by .
Step 6.1.2.1.4
The exact value of is .
Step 6.1.2.2
Subtract from .
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
Simplify each term.
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Step 6.2.2.1.1
Combine the numerators over the common denominator.
Step 6.2.2.1.2
Add and .
Step 6.2.2.1.3
Cancel the common factor of and .
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Step 6.2.2.1.3.1
Factor out of .
Step 6.2.2.1.3.2
Cancel the common factors.
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Step 6.2.2.1.3.2.1
Factor out of .
Step 6.2.2.1.3.2.2
Cancel the common factor.
Step 6.2.2.1.3.2.3
Rewrite the expression.
Step 6.2.2.1.4
The exact value of is .
Step 6.2.2.2
Subtract from .
Step 6.2.2.3
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
Simplify each term.
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Step 6.3.2.1.1
Combine the numerators over the common denominator.
Step 6.3.2.1.2
Add and .
Step 6.3.2.1.3
Cancel the common factor of .
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Step 6.3.2.1.3.1
Cancel the common factor.
Step 6.3.2.1.3.2
Divide by .
Step 6.3.2.1.4
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 6.3.2.1.5
The exact value of is .
Step 6.3.2.1.6
Multiply by .
Step 6.3.2.2
Subtract from .
Step 6.3.2.3
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
Simplify each term.
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Step 6.4.2.1.1
Combine the numerators over the common denominator.
Step 6.4.2.1.2
Add and .
Step 6.4.2.1.3
Cancel the common factor of and .
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Step 6.4.2.1.3.1
Factor out of .
Step 6.4.2.1.3.2
Cancel the common factors.
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Step 6.4.2.1.3.2.1
Factor out of .
Step 6.4.2.1.3.2.2
Cancel the common factor.
Step 6.4.2.1.3.2.3
Rewrite the expression.
Step 6.4.2.1.4
Apply the reference angle by finding the angle with equivalent trig values in the first quadrant.
Step 6.4.2.1.5
The exact value of is .
Step 6.4.2.2
Subtract from .
Step 6.4.2.3
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
Simplify each term.
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Step 6.5.2.1.1
Combine the numerators over the common denominator.
Step 6.5.2.1.2
Add and .
Step 6.5.2.1.3
Cancel the common factor of and .
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Step 6.5.2.1.3.1
Factor out of .
Step 6.5.2.1.3.2
Cancel the common factors.
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Step 6.5.2.1.3.2.1
Factor out of .
Step 6.5.2.1.3.2.2
Cancel the common factor.
Step 6.5.2.1.3.2.3
Rewrite the expression.
Step 6.5.2.1.3.2.4
Divide by .
Step 6.5.2.1.4
Subtract full rotations of until the angle is greater than or equal to and less than .
Step 6.5.2.1.5
The exact value of is .
Step 6.5.2.2
Subtract from .
Step 6.5.2.3
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: ( to the left)
Vertical Shift:
Step 8