In Exercises 61–86, use reference angles to find the exact value of each expression. Do not use a calculator. sin(-240°)
Ch. 1 - Angles and the Trigonometric Functions

1장, 문제 1
A point P(x, y) is shown on the unit circle corresponding to a real number t. Find the values of the trigonometric functions at t.
<IMAGE>
검증된 단계별 안내1
Recall that for a point \(P(x, y)\) on the unit circle corresponding to an angle \(t\), the coordinates are given by \(x = \cos(t)\) and \(y = \sin(t)\).
Identify the values of \(x\) and \(y\) from the point \(P\) on the unit circle. These values represent \(\cos(t)\) and \(\sin(t)\) respectively.
Use the definitions of the six trigonometric functions in terms of \(\sin(t)\) and \(\cos(t)\):
\(\sin(t) = y\)
\(\cos(t) = x\)
\(\tan(t) = \frac{y}{x}\) (provided \(x \neq 0\))
\(\csc(t) = \frac{1}{y}\) (provided \(y \neq 0\))
\(\sec(t) = \frac{1}{x}\) (provided \(x \neq 0\))
\(\cot(t) = \frac{x}{y}\) (provided \(y \neq 0\)).
Substitute the values of \(x\) and \(y\) into these formulas to express each trigonometric function in terms of the coordinates of point \(P\).
Check the quadrant of the angle \(t\) based on the signs of \(x\) and \(y\) to determine the signs of the trigonometric functions, ensuring the correct values for each function.

비슷한 문제에 대한 검증된 영상 답변:
이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
5m도움이 되었나요?
주요 개념
질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.
Unit Circle Definition
The unit circle is a circle with radius 1 centered at the origin of the coordinate plane. Each point P(x, y) on the unit circle corresponds to an angle t, where x = cos(t) and y = sin(t). This relationship allows us to find trigonometric function values directly from coordinates.
추천 영상:
Introduction to the Unit Circle
Trigonometric Functions on the Unit Circle
The six trigonometric functions—sine, cosine, tangent, cosecant, secant, and cotangent—can be defined using the coordinates of point P on the unit circle. Specifically, sin(t) = y, cos(t) = x, and tan(t) = y/x, with reciprocal functions defined accordingly.
추천 영상:
Sine, Cosine, & Tangent on the Unit Circle
Sign of Trigonometric Functions in Quadrants
The sign of sine, cosine, and tangent depends on the quadrant where point P lies. For example, sine is positive in quadrants I and II, cosine is positive in quadrants I and IV, and tangent is positive in quadrants I and III. This helps determine the correct sign of function values.
추천 영상:
Quadratic Formula
관련 실천
교과서 질문
677
views
교과서 질문
In Exercises 57–70, find a positive angle less than or that is coterminal with the given angle. -150°
563
views
교과서 질문
In Exercises 41–56, use the circle shown in the rectangular coordinate system to draw each angle in standard position. State the quadrant in which the angle lies. When an angle's measure is given in radians, work the exercise without converting to degrees.
420°
625
views
교과서 질문
Find the reference angle for each angle.
4.7
711
views
교과서 질문
In Exercises 1–8, use the Pythagorean Theorem to find the length of the missing side of each right triangle. Then find the value of each of the six trigonometric functions of θ.
719
views
교과서 질문
In Exercises 61–86, use reference angles to find the exact value of each expression. Do not use a calculator. tan(9𝜋/2)
732
views
