Solve for ? cos(x)=5/13

Take the inverse cosine of both sides of the equation to extract from inside the cosine.
Evaluate .
The cosine function is positive in the first and fourth quadrants. To find the second solution, subtract the reference angle from to find the solution in the fourth quadrant.
Simplify .
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Multiply by .
Subtract from .
Find the period.
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The period of the function can be calculated using .
Replace with in the formula for period.
Solve the equation.
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The absolute value is the distance between a number and zero. The distance between and is .
Divide by .
The period of the function is so values will repeat every radians in both directions.
, for any integer
Solve for ? cos(x)=5/13

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Charlie Trom

Lucy Evel

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