AP Precalculus / Unit 3: Trigonometric and Polar Functions
3.4 Sine and Cosine Function Graphs
Notes
- $y=\sin x$: starts at 0, peaks at $\displaystyle \frac{\pi}{2}$. $y=\cos x$: starts at 1.
- Both have period $2\pi$, amplitude 1, range $[-1,1]$.
- $\displaystyle \cos x=\sin\left(x+\frac{\pi}{2}\right)$.
Practice
The range of $y=\sin x$:
It oscillates between $-1$ and 1.
$y=\cos x$ has a maximum at:
$\cos0=1$.
The zeros of $\sin x$ are at:
$0, \pi, 2\pi, \dots$
Ready for more? Take the Unit 3 test.