Mystery Sinusoid Quiz: Mystery Sinusoid 2.5 2 1.5 1 0.5 t 0 -0.5 -1 -1.5 -2 -2.5 -2 -1 0 1 2 3 4 5 6 7 Fig. 1. Mystery sinusoid. The graph of a sinusoidal function is displayed. The problem is to ex­ press it in the standard form f (t) = A cos(ωt − φ). Choices: � � a) 2 cos �4πt + π4� d) 2 cos π4 t − π4 � � b) 2 cos π4 t + π4 e) 2 cos (4t + 1) � � c) 2 cos 4πt − π4 f) 2 cos (4t − 1) Pick what you think is the correct choice and then look at the answer. 8 MIT OpenCourseWare http://ocw.mit.edu 18.03SC Differential Equations�� Fall 2011 �� For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.