Find the period and phase shift of y tan pix pi4 and sketc
     Find the period and phase shift of y = tan (pix + pi/4) and sketch its graph.  The beam from an island light house completes one rotation every two minutes. At time t (in minutes), the distance d (in miles) between the closest point on shore to the island and the light on the shoreline is given by d(t) = 3 tan(pi t).  Find d(0.15), d(0.25) and d(0.45).  What happens to the distance d as t approaches 1/2? 
  
  Solution
y = tan ( pi x + pi/4 )
standard equation of tan function is given by
y = A tan ( Bx + C ) + D
where, A is amplitude
period is pi/ B
phase shift = -C/B
therefore, compring our problem equation with standard equation
we get period = pi / pi = 1
phase shift = - pi/4 / pi = -1/4

