Graphs of the Sine and Cosine Functions
Properties of functions can be observed from their graphs. We begin by graphing the sine and the cosine functions. We make a table of values, plot the points, and then connect those points with a smooth curve. It is helpful to first draw a unit circle and label a few points with coordinates. We can either use the coordinates as the function values or find approximate sine and cosine values directly with a calculator.
s | $\text{sin}\text{}s$ | $\text{cos}\text{}s$ |
---|---|---|
0 | 0 | 1 |
$\pi /6$ | 0.5 | 0.8660 |
$\pi /4$ | 0.7071 | 0.7071 |
$\pi /3$ | 0.8660 | 0.5 |
$\pi /2$ | 1 | 0 |
$3\pi /4$ | 0.7071 | $-0.7071$ |
$\pi $ | 0 | $-1$ |
$5\pi /4$ | $-0.7071$ | $-0.7071$ |
Get Algebra and Trigonometry, 5th Edition now with O’Reilly online learning.
O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.