Question

Which function describes the graph below? On a coordinate plane, a curve crosses the y-axis at (0, 7), decreases to negative 1, and then increases again to 7. y = 8 cosine (x) + 3 y = 4 cosine (x) + 3 y = 4 sine (x) + 3 y = 8 sine (x) + 3

Answer 1

Pretty sure its' b (y=4Cos(x)+3)

Explanation:

Take the max minus the min, equals 8 then times 1/2 equals 4.

Since it starts at the max, that is a characteristic of cosine NOT sine.

P.s I know this is late, but for other people

Answer 2

y = 4 cosine (x) + 3

Explanation:

A curve crosses the y-axis at (0, 7)

This means that when x = 0, y = 7

We have that:

sin(0) = 0, cos(0) = 1.

Let's see which of the functions respect this condition:

y = 8 cosine (x) + 3

y(0) = 8cos(0) + 3 = 8 + 3 = 11. Incorrect.

y = 4 cosine (x) + 3

y(0) = 4cos(0) + 3 = 4 + 3 = 7. Correct.

y = 4 sine (x) + 3

y(0) = 4sin(0) + 3 = 0 + 3 = 3. Incorrect.

y = 8 sine (x) + 3

y(0) = 8sin(0) + 3 = 0 + 3 = 3. Incorrect.

Decreases to negative 1, and then increases again to 7.

This means that the amplitude is 7-(-1) = 8, which means that the term which multiplies the function is 8/2 = 4. From above, we have already seen that the answer is y = 4 cosine (x) + 3.