Question

Can someone please help me understand this question: The curve above is the graph of a sinusoidal function. It goes through the point (7,4). Find a sinusoidal function that matches the given graph.

Answer 1

The graph

Answer 2

In the form of y=Asin(Bx-C)+D

Answer 3

Okay, so we know A = 4, right?

Answer 4

Yep

Answer 5

I am having the most trouble finding B and putting it into the equation

Answer 6

I understand how to find the two points, and comparing it to the sin graph. I just don't understand how to use them and find B and C.

Answer 7

Hang on bro

Answer 8

No worries.

Answer 9

1. Okay, so what you're supposed to do for this is start with the parent function, which in this case is cos(x).

2. Next we see that cos(x) is actually flipped across the x-axis to get y = -cos(x).

3. Then it is stretched vertically by 4 to get y = -4cos(x)

4. Now it is not phase shifted or vertically shifted.

Thus:

A = -4
B = 1
C = 0
D = 0

Answer 10

Thanks

Answer 11

You're welcome