1) Give the exact value of the following: 4cos(π/4)

2) Evaluate the following expression whenxisπ/4. Use the exact value:

5cos(2x)

3) For the following expression, find the value ofythat corresponds to each value ofx, then write your results as ordered pairs (x,y). (Enter your answers from smallest to largestx-value.)

y=1/4cos(x)

x=0,π/2,π, 3π/2, 2π

thxs!