Oftentimes you’ll be presented with the properties of the wave and will be expected to create an equation from them. For example, you may be given the amplitude, period, phase-shift or told that it reflects about the *x* axis or has a height of *n*. Whatever the case is, you always start one of the general formulas:

- y =
**a**⋅sin(**b**x +**c**) +**d** - y =
**a**⋅cos(**b**x +**c**) +**d**

Some general tips to follow:

- If given the amplitude or
height, begin by filling in the factorafirst.- If given the period and phase-shift, you need to find the value
busing the period before you can find the value forc.- If the period and phase-shift is given without units (such as degrees °), the equation is in radians.
- Always have a summary of the formulas ready or memorized: