Chapter 5 - Section 5.3 - Trigonometric Graphs - 5.3 Exercises - Page 429: 19

amplitude=1 period =$ 2\pi$ graph: .

See p. 424. For $y=a\sin k(x-b),\qquad y=a\cos k(x-b)$, $(k>0)$ Amplitude: $|a|$, Period: $\displaystyle \frac{2\pi}{k}$, Horizontal shift: $b$ ------------------ $y=\cos 2x$ $a=1 , k=2, b=0$ So, amplitude=1 period =$ 2\pi$ To graph, begin with $f(x)=\cos x$ and horizontally compress by factor 2.