Use reference triangles in an appropriate quadrant to find the angles in Exercises 1–8.
1. a. arctan 1

검증된 단계별 안내

Recall that \( \arctan(x) \) is the inverse tangent function, which gives the angle \( \theta \) whose tangent is \( x \). So, we want to find \( \theta \) such that \( \tan(\theta) = 1 \).

Identify the reference angle by considering the positive value 1 for tangent. Since \( \tan(\theta) = \frac{\text{opposite}}{\text{adjacent}} \), a ratio of 1 means the opposite and adjacent sides of the reference triangle are equal.

Recognize that the angle with tangent 1 in the first quadrant is \( \frac{\pi}{4} \) radians (or 45 degrees), because in a right triangle with equal legs, the angles opposite those legs are equal.

Since the problem does not specify a quadrant other than the principal value range of \( \arctan \), which is \( \left(-\frac{\pi}{2}, \frac{\pi}{2}\right) \), the angle is simply the reference angle \( \frac{\pi}{4} \).

Therefore, the solution is \( \theta = \arctan(1) = \frac{\pi}{4} \), using the reference triangle in the first quadrant.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

도움이 되었나요?

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Inverse Trigonometric Functions

Inverse trigonometric functions, like arctan, return the angle whose trigonometric ratio equals a given value. For example, arctan(1) gives the angle whose tangent is 1. Understanding their ranges and outputs is essential for finding correct angle measures.

Reference Triangles

Reference triangles are right triangles used to relate trigonometric ratios to angles in different quadrants. By considering the signs of sides and angles, they help determine the actual angle corresponding to a trigonometric value in any quadrant.

Quadrants and Angle Sign Conventions

The coordinate plane is divided into four quadrants, each with specific sign rules for sine, cosine, and tangent. Knowing which quadrant an angle lies in helps assign the correct sign and value to the angle found using inverse trig functions.

Use reference triangles in an appropriate quadrant to find the angles in Exercises 1–8.1. a. arctan 1