### All Precalculus Resources

## Example Questions

### Example Question #1 : Sum And Difference Identities For Tangent

In the problem below, and .

Find

.

**Possible Answers:**

**Correct answer:**

Explanation:

Since and is in quadrant I, we can say that and and therefore:

.

So

.

Since and is in quadrant I, we can say that and and therefore:

.

So .

Using the tangent sum formula, we see:

### Example Question #2 : Sum And Difference Identities For Tangent

In the problem below, and .

Find

.

**Possible Answers:**

**Correct answer:**

Explanation:

Since and is in quadrant I, we can say that and and therefore:

.

So .

Since and is in quadrant I, we can say that and and therefore:

.

So .

Using the tangent sum formula, we see:

### Example Question #3 : Sum And Difference Identities For Tangent

Given that and , find .

**Possible Answers:**

**Correct answer:**

Explanation:

Jump straight to the tangent sum formula:

From here plug in the given values and simplify.

### Example Question #4 : Sum And Difference Identities For Tangent

Which of the following expressions best represents ?

**Possible Answers:**

**Correct answer:**

Explanation:

Write the identity for .

Set the value of the angle equal to .

Substitute the value of into the identity.