### All Precalculus Resources

## Example Questions

### Example Question #1 : Evaluate Expressions That Include The Inverse Tangent, Cosecant, Secant, Or Cotangent Function

Approximate:

**Possible Answers:**

**Correct answer:**

:

There is a restriction for the range of the inverse tangent function from .

The inverse tangent of a value asks for the angle where the coordinate lies on the unit circle under the condition that . For this to be valid on the unit circle, the must be very close to 1, with an value also very close to zero, but cannot equal to zero since would be undefined.

The point is located on the unit circle when , but is invalid due to the existent asymptote at this angle.

An example of a point very close to that will yield can be written as:

Therefore, the approximated rounded value of is .

### Example Question #1 : Inverse Trigonometric Functions

Evaluate:

**Possible Answers:**

**Correct answer:**

To determine the value of , solve each of the terms first.

The inverse cosine has a domain and range restriction.

The domain exists from , and the range from . The inverse cosine asks for the angle when the x-value of the existing coordinate is . The only possibility is since the coordinate can only exist in the first quadrant.

The inverse sine also has a domain and range restriction.

The domain exists from , and the range from . The inverse sine asks for the angle when the y-value of the existing coordinate is . The only possibility is since the coordinate can only exist in the first quadrant.

Therefore:

### Example Question #1 : Inverse Trigonometric Functions

Evaluate the following:

**Possible Answers:**

**Correct answer:**

For this particular problem we need to recall that the inverse cosine cancels out the cosine therefore,

.

So the expression just becomes

From here, recall the unit circle for specific angles such as .

Thus,

.

### Example Question #1 : Inverse Trigonometric Functions

Determine the value of in degrees.

**Possible Answers:**

**Correct answer:**

Rewrite and evaluate .

The inverse sine of one-half is since is the y-value of the coordinate when the angle is .

To convert from radians to degrees, replace with 180.

### Example Question #851 : Pre Calculus

Evaluate the following expression:

**Possible Answers:**

**Correct answer:**

This one seems complicated, but becomes considerably easier once you implement the fact that the composite cancels out to 1 and you are left with which is equal to 1

### Example Question #1 : Inverse Trigonometric Functions

Evaluate:

**Possible Answers:**

**Correct answer:**

### Example Question #31 : Graphs And Inverses Of Trigonometric Functions

Approximate the following:

**Possible Answers:**

**Correct answer:**

This one is rather simple with knowledge of the unit circle: the value is extremely close to zero, of which always

### Example Question #1 : Inverse Trigonometric Functions

Given that and that is acute, find the value of without using a calculator.

**Possible Answers:**

**Correct answer:**

Given the value of the opposite and hypotenuse sides from the sine expression (3 and 4 respectively) we can use the Pythagorean Theorem to find the 3rd side (we’ll call it “t”): . From here we can easily deduce the value of (the adjacent side over the opposite side)

### Example Question #1 : Inverse Trigonometric Functions

Given that and that is acute, find the value of without using a calculator.

Given the value of the opposite and hypotenuse sides from the sine expression (3 and 4 respectively) we can use the Pythagorean Theorem to find the 3rd side (we’ll call it “t”): .

From here we can deduce the value of (the adjacent side over the opposite side) and so the answer is .

### Example Question #1 : Inverse Trigonometric Functions

Evaluate the following expression:

**Possible Answers:**

**Correct answer:**

This one seems complicated but becomes considerably easier once you implement the fact that the composite cancels out to and you are left with which is equal to , and so the answer is .