Skip to main content
Ch. 1 - Angles and the Trigonometric Functions
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601당신이 사용하는 게 아니라요?교과서 변경
1장, 문제 6

In Exercises 1–8, a point on the terminal side of angle θ is given. Find the exact value of each of the six trigonometric functions of θ. (5, -5)

검증된 단계별 안내
1
Identify the coordinates of the point on the terminal side of angle \( \theta \). Here, the point is \( (5, -5) \), so \( x = 5 \) and \( y = -5 \).
Calculate the radius \( r \), which is the distance from the origin to the point, using the formula \( r = \sqrt{x^2 + y^2} \). Substitute the values to get \( r = \sqrt{5^2 + (-5)^2} \).
Recall the definitions of the six trigonometric functions in terms of \( x \), \( y \), and \( r \): \[ \sin \theta = \frac{y}{r}, \quad \cos \theta = \frac{x}{r}, \quad \tan \theta = \frac{y}{x}, \quad \csc \theta = \frac{r}{y}, \quad \sec \theta = \frac{r}{x}, \quad \cot \theta = \frac{x}{y} \]
Substitute the values of \( x \), \( y \), and \( r \) into each of the six functions to express them exactly in terms of radicals and integers.
Simplify each expression if possible, keeping in mind the signs of \( x \), \( y \), and \( r \) to determine the correct sign of each trigonometric function.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
7m
도움이 되었나요?

주요 개념

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

Coordinates and the Terminal Side of an Angle

The terminal side of an angle θ in standard position passes through a point (x, y). This point helps determine the angle's trigonometric values by relating x and y to the radius (r), which is the distance from the origin to the point, calculated using the Pythagorean theorem.
추천 영상:
05:32
Intro to Polar Coordinates

Definition of the Six Trigonometric Functions

The six trigonometric functions—sine, cosine, tangent, cosecant, secant, and cotangent—are ratios involving x, y, and r. Specifically, sin(θ) = y/r, cos(θ) = x/r, tan(θ) = y/x, and their reciprocals define the other three functions. These ratios are essential for finding exact values.
추천 영상:
6:04
Introduction to Trigonometric Functions

Sign of Trigonometric Functions Based on Quadrants

The signs of x, y, and r determine the sign of each trigonometric function. Since r is always positive, the signs depend on the quadrant where the point lies. For (5, -5), the point is in the fourth quadrant, affecting the positivity or negativity of sine, cosine, and tangent values.
추천 영상:
6:04
Introduction to Trigonometric Functions