Trigonometry Examples

Find the Exact Value cos(1pi)
cos(1π)
Step 1
Multiply π by 1.
cos(π)
Step 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.
-cos(0)
Step 3
The exact value of cos(0) is 1.
-11
Step 4
Multiply -1 by 1.
-1
 [x2  12  π  xdx ]