Question

Find the equation of the form y=Acos(Bx+C) that produces the graph below. (*Will insert pic.)

Answer 1

Let's look at each variable in the equation one at a time.

A is the amplitude, which is basically how far the wave gets from 0. What's the y value pf the highest point? That's the amplitude.

Answer 2

2, but is it possible to get -2 the teacher didnt mark it wrong so Im confused

Answer 3

You could say that the amplitude is -2, sort of.
If you were to multiply that graph by -1, it would be the same graph, just shifted over some, right?

Answer 4

I guess, the graphs just really confuse me. so to start with the A would =2, but positive right?

Answer 5

Yeah. Let's just keep it at +2 for now.
You can have negative amplitudes, but it's not really worth the confusion.

Answer 6

Let's find the next variable, B.

B is the frequency of the function. We can find it with the equation:
\[B = \frac{2 \pi}{T}\]
Where T is the time it takes the function to go through a single cycle

Answer 7

2?

Answer 8

I split it into halfs I think and got pi but more as guessing than really knowing and then divided 2pi by pi

Answer 9

Yup! So, B = 2