Find the period of function y = 3cos(4x-pi)? Determine the graph of y = 2sin(3x+pi/4) is attain from graph of y = 2sin(3x) by shifting 3) determine length of the arc with angle 120 degree in the circle with 12 meters. 4) Compute all values of t in interval [0,2pi] which satisfy 2 cos t + 1 =0.