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Ch. 3 - Radian Measure and The Unit Circle
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161당신이 사용하는 게 아니라요?교과서 변경
4장, 문제 61

Work each problem. See Example 5. Arc Length A circular sector has an area of 50 in² . The radius of the circle is 5 in. What is the arc length of the sector?

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1
Recall the formula for the area of a circular sector: \(\text{Area} = \frac{1}{2} r^2 \theta\), where \(r\) is the radius and \(\theta\) is the central angle in radians.
Substitute the given values into the area formula: \(50 = \frac{1}{2} \times 5^2 \times \theta\).
Simplify the equation to solve for \(\theta\): \(50 = \frac{1}{2} \times 25 \times \theta\) which simplifies to \(50 = 12.5 \times \theta\).
Isolate \(\theta\) by dividing both sides by 12.5: \(\theta = \frac{50}{12.5}\).
Use the arc length formula \(s = r \theta\) to find the arc length, substituting \(r = 5\) and the value of \(\theta\) found in the previous step.

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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.

Area of a Circular Sector

The area of a circular sector is given by the formula A = (1/2) * r² * θ, where r is the radius and θ is the central angle in radians. This formula relates the sector's area to the radius and the angle, allowing calculation of one if the others are known.
추천 영상:
가이드 코스
4:02
Calculating Area of SAS Triangles

Arc Length of a Circle

The arc length (s) of a sector is calculated by s = r * θ, where r is the radius and θ is the central angle in radians. This formula connects the linear distance along the circle's edge to the radius and angle.
추천 영상:
06:11
Introduction to the Unit Circle

Converting Between Area and Arc Length Using the Central Angle

To find the arc length from the sector's area and radius, first solve for the central angle θ using the area formula, then use θ to find the arc length. This process links the two measurements through the angle, enabling the solution.
추천 영상:
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Convert Points from Rectangular to Polar