Video Transcript
Assign each plot shown in the graph
below to the function it represents.
Here, we see we have two very
similar-looking graphs. These graphs are clearly
periodic. They appear to repeat every two 𝜋
radians. Remember, that’s repeating every
360 degrees. We see they have maximums at one
and minimums at negative one, respectively. In fact, we know that we can
describe the graphs of the sine and cosine functions in the same way.
The main difference is where these
graphs intersect the 𝑦-axis. 𝑦 equals sin of 𝑥 passes through
the 𝑦-axis at zero, whereas 𝑦 equals cos of 𝑥 passes through at one. And we said, of course, that both
have a period of 360 degrees or two 𝜋 radians, maxima at one, and minima at
negative one. This means that the red plot which
intersects the 𝑦-axis at one must be the cosine curve, whereas the blue plot must
be the sine curve.
