Trigonometry Examples

Solve for x 6tan(x)^2-18=0
Step 1
Add to both sides of the equation.
Step 2
Divide each term in by and simplify.
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Step 2.1
Divide each term in by .
Step 2.2
Simplify the left side.
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Step 2.2.1
Cancel the common factor of .
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Step 2.2.1.1
Cancel the common factor.
Step 2.2.1.2
Divide by .
Step 2.3
Simplify the right side.
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Step 2.3.1
Divide by .
Step 3
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
Step 4
The complete solution is the result of both the positive and negative portions of the solution.
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Step 4.1
First, use the positive value of the to find the first solution.
Step 4.2
Next, use the negative value of the to find the second solution.
Step 4.3
The complete solution is the result of both the positive and negative portions of the solution.
Step 5
Set up each of the solutions to solve for .
Step 6
Solve for in .
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Step 6.1
Take the inverse tangent of both sides of the equation to extract from inside the tangent.
Step 6.2
Simplify the right side.
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Step 6.2.1
The exact value of is .
Step 6.3
The tangent function is positive in the first and third quadrants. To find the second solution, add the reference angle from to find the solution in the fourth quadrant.
Step 6.4
Simplify .
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Step 6.4.1
To write as a fraction with a common denominator, multiply by .
Step 6.4.2
Combine fractions.
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Step 6.4.2.1
Combine and .
Step 6.4.2.2
Combine the numerators over the common denominator.
Step 6.4.3
Simplify the numerator.
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Step 6.4.3.1
Move to the left of .
Step 6.4.3.2
Add and .
Step 6.5
Find the period of .
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Step 6.5.1
The period of the function can be calculated using .
Step 6.5.2
Replace with in the formula for period.
Step 6.5.3
The absolute value is the distance between a number and zero. The distance between and is .
Step 6.5.4
Divide by .
Step 6.6
The period of the function is so values will repeat every radians in both directions.
, for any integer
, for any integer
Step 7
Solve for in .
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Step 7.1
Take the inverse tangent of both sides of the equation to extract from inside the tangent.
Step 7.2
Simplify the right side.
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Step 7.2.1
The exact value of is .
Step 7.3
The tangent function is negative in the second and fourth quadrants. To find the second solution, subtract the reference angle from to find the solution in the third quadrant.
Step 7.4
Simplify the expression to find the second solution.
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Step 7.4.1
Add to .
Step 7.4.2
The resulting angle of is positive and coterminal with .
Step 7.5
Find the period of .
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Step 7.5.1
The period of the function can be calculated using .
Step 7.5.2
Replace with in the formula for period.
Step 7.5.3
The absolute value is the distance between a number and zero. The distance between and is .
Step 7.5.4
Divide by .
Step 7.6
Add to every negative angle to get positive angles.
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Step 7.6.1
Add to to find the positive angle.
Step 7.6.2
To write as a fraction with a common denominator, multiply by .
Step 7.6.3
Combine fractions.
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Step 7.6.3.1
Combine and .
Step 7.6.3.2
Combine the numerators over the common denominator.
Step 7.6.4
Simplify the numerator.
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Step 7.6.4.1
Move to the left of .
Step 7.6.4.2
Subtract from .
Step 7.6.5
List the new angles.
Step 7.7
The period of the function is so values will repeat every radians in both directions.
, for any integer
, for any integer
Step 8
List all of the solutions.
, for any integer
Step 9
Consolidate the solutions.
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Step 9.1
Consolidate and to .
, for any integer
Step 9.2
Consolidate and to .
, for any integer
, for any integer