Cosine graphs and period

y=cos x Cosine starts at cos0=1, with quarter-cycle values 1,0,-1,0,1. **Function** | **0 (0)** | **90 ((pi)/(2))** | **180 (pi)** | **270 ((3pi)/(2))** | **360 (2pi)** cos x | 1 | 0 | -1 | 0 | 1 y=acos(bx), a,b>0 Amplitude=a T= 360 b or 2pib **Function** | **Amplitude** | **Period (degrees)** | **Period (radians)** | **Maximum value of y** | **Minimum value of y** y=10cos 3x | 10 | 120 | (2pi)/(3) | 10 | -10 y=4cos 2x | 4 | 180 | pi | 4 | -4 y=cos(2x)/(3) | 1 | 540 | 3pi | 1 | -1 Mark quarter-period steps and the pattern a,0,-a,0,a. Label the extremes and stop at the stated endpoints. Example: y=5cos2x, 0 <= x <= pi Amplitude 5; period pi. Quarter-period points: (0,5), (4,0), (2,-5), (3pi4,0), (pi,5).