Problem 15 - Precalculus Essentials

Question

Find the exact value of each expression. $$\tan ^{-1} 0$$

Step-by-Step Solution

Answer

The exact value of \( \tan^{-1} 0 \) is 0.

Step 1: The Function Value

The function provided in the exercise is \( \tan^{-1} 0 \) , which implies we need the angle whose tangent is 0.

Step 2: Find the Angle With Zero Tangent

Recall from trigonometry, the tangent of an angle is 0 at 0 degrees or 0 radians, because \( \tan 0 = 0 \). Hence, the angle we're looking for is 0.

Key Concepts

Trigonometric Functions

Trigonometric functions are foundational elements in mathematics, especially in the study of geometry and periodic phenomena. They relate the angles of a triangle to the lengths of its sides. Common trigonometric functions include sine, cosine, and tangent. Each of these functions has a specific relationship to the angles and sides of a right-angled triangle.
The tangent function specifically is defined as the ratio of the opposite side to the adjacent side for any given angle in a right triangle. Therefore, if you know two sides of a right triangle, you can find the tangent of the angle between them. This is immensely useful in a variety of fields like engineering, physics, and even in computer graphics. Trigonometric functions also extend beyond triangles, being applied to model waves and oscillations in more complex scenarios.

Tangent

The tangent function, abbreviated as 'tan', is unique among the trigonometric functions as it is the ratio of sine to cosine. In mathematical terms, it is expressed as:

• \( \tan \theta = \frac{\sin \theta}{\cos \theta} \)

The tangent function is known for its property of being zero when the angle is 0 degrees or 0 radians. This is because the sine of 0 is 0, leading to:

• \( \tan 0 = \frac{0}{1} = 0 \)

The inverse tangent, or arctangent, function is used to determine the angle whose tangent is a given number. When working with \( \tan^{-1} 0 \), we're asked to find an angle whose tangent is 0, which comfortably brings us back to 0 degrees or 0 radians.
Moreover, tangent functions have unique properties such as periodicity, meaning they repeat their values in continual cycles, and asymptotes, where the function goes to infinity indicating it's undefined at certain angles.

Angle Measurement

Understanding angle measurement is crucial when working with trigonometric functions. Angles can be measured in degrees or radians, with 360 degrees making a full circle or equivalently \( 2\pi \) radians. This dual measurement system makes it essential to be comfortable converting between degrees and radians.
In practical terms, 0 degrees is often considered a starting point for angle measurement in trigonometry. It corresponds to 0 radians as well. When dealing with inverse trigonometric functions, such as \( \tan^{-1} \) in the original exercise, finding an angle from a given trigonometric value often results in standard angle positions like 0 degrees or multiples of 90 degrees.
For instance, when \( \tan^{-1} 0 \) asks for an angle with a tangent of 0, the answer of 0 degrees or 0 radians comes naturally as a familiar anchor point in angle measurement. Mastery of angle measurement is vital across all sciences as it allows for clear communication and understanding of positional and relational data in mathematical and real-world models.