### Home > CCA2 > Chapter 7 > Lesson 7.2.2 > Problem 7-129

Find an equation for each graph below. Homework Help ✎

a.

b.

c.

d.

Use the general equation *y* = *a* · sin(*x* − *h*) + *k*.

Determine the value for each of the three parameters.

First identify a convenient locator point.

In this case, we will use:

The *x*-value of the point represents the horizontal shift.

The *y*-value of the point represents the vertical shift.

The amplitude (a) is the distance from the midline (*k*) to the highest point.

In this case *k* = 2 and the highest point is 3, so *a* = 1.

Since the graph increases from the locator point in the same way *y* = sin *x* does, *a* is positive.

See part (a).

Pay careful attention to the scale on the *y*-axis when determining *a* and *k*.

notice the first cycle of the graph is an inverted sine curve, so the *a* value will be negative.

See part (a).

See parts (a) and (c).