Examples
,
Step 1
Replace the variable with in the expression.
Step 2
Step 2.1
Cancel the common factor.
Step 2.2
Divide by .
Step 3
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 4
The exact value of is .
Step 5
Multiply by .