# High School Math : Understanding Sine, Cosine, and Tangent

## Example Questions

### Example Question #1 : Trigonometry

If the polar coordinates of a point are , then what are its rectangular coordinates?

Explanation:

The polar coordinates of a point are given as , where r represents the distance from the point to the origin, and  represents the angle of rotation. (A negative angle of rotation denotes a clockwise rotation, while a positive angle denotes a counterclockwise rotation.)

The following formulas are used for conversion from polar coordinates to rectangular (x, y) coordinates.

In this problem, the polar coordinates of the point are  , which means that  and . We can apply the conversion formulas to find the values of x and y.

The rectangular coordinates are .

The answer is .

What is the ?

Explanation:

### Example Question #3 : Trigonometry

In the right triangle above, which of the following expressions gives the length of y?

Explanation:

is defined as the ratio of the adjacent side to the hypotenuse, or in this case . Solving for y gives the correct expression.

### Example Question #4 : Trigonometry

What is the cosine of ?

Explanation:

The pattern for the side of a  triangle is .

Since , we can plug in our given values.

Notice that the 's cancel out.

### Example Question #1 : Trigonometry

If , what is  if  is between  and ?