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Ch. 1 - Angles and the Trigonometric Functions
Blitzer - Trigonometry 3rd Edition
Blitzer3rd EditionTrigonometryISBN: 9780137316601당신이 사용하는 게 아니라요?교과서 변경
1장, 문제 5

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.
Right triangle PQR with sides 28 and 53, angle θ at vertex R.

검증된 단계별 안내
1
Identify the sides of the right triangle relative to angle \( \theta \) at vertex R. The hypotenuse is the side opposite the right angle, which is \( PR = 53 \). The side opposite \( \theta \) is \( PQ = 28 \), and the adjacent side to \( \theta \) is \( QR \), which is unknown.
Use the Pythagorean Theorem to find the missing side \( QR \). The theorem states: \(QR^2 + PQ^2 = PR^2\) Substitute the known values: \(QR^2 + 28^2 = 53^2\)
Solve for \( QR^2 \): \(QR^2 = 53^2 - 28^2\) Then take the square root to find \( QR \): \(QR = \sqrt{53^2 - 28^2}\)
Once you have the length of \( QR \), find the six trigonometric functions of \( \theta \) using the definitions relative to angle \( \theta \): - \( \sin \theta = \frac{\text{opposite}}{\text{hypotenuse}} = \frac{PQ}{PR} \) - \( \cos \theta = \frac{\text{adjacent}}{\text{hypotenuse}} = \frac{QR}{PR} \) - \( \tan \theta = \frac{\text{opposite}}{\text{adjacent}} = \frac{PQ}{QR} \) - \( \csc \theta = \frac{1}{\sin \theta} = \frac{PR}{PQ} \) - \( \sec \theta = \frac{1}{\cos \theta} = \frac{PR}{QR} \) - \( \cot \theta = \frac{1}{\tan \theta} = \frac{QR}{PQ} \)
Substitute the known side lengths into these formulas to express each trigonometric function in terms of numbers. This completes the process of finding the missing side and the six trigonometric functions of \( \theta \).

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이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
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주요 개념

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

Pythagorean Theorem

The Pythagorean Theorem states that in a right triangle, the square of the hypotenuse (longest side) equals the sum of the squares of the other two sides. It is expressed as a² + b² = c², where c is the hypotenuse. This theorem helps find the missing side length when two sides are known.
추천 영상:
5:19
Solving Right Triangles with the Pythagorean Theorem

Right Triangle Trigonometric Functions

The six trigonometric functions—sine, cosine, tangent, cosecant, secant, and cotangent—relate the angles of a right triangle to the ratios of its sides. For an angle θ, sine is opposite/hypotenuse, cosine is adjacent/hypotenuse, and tangent is opposite/adjacent. The reciprocal functions are cosecant, secant, and cotangent.
추천 영상:
6:04
Introduction to Trigonometric Functions

Identifying Sides Relative to an Angle

In a right triangle, the side opposite the right angle is the hypotenuse. For a given angle θ, the side directly opposite is the opposite side, and the side next to θ (but not the hypotenuse) is the adjacent side. Correctly identifying these sides is essential for applying trigonometric functions accurately.
추천 영상:
4:18
Finding Missing Side Lengths