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ARCSINE

Arcsine

Definition Of Arcsine

Arcsine is the inverse function of sine. It is also written as arcsin or sin-1. If y = sin x, then x = arcsin y.

Examples of Arcsine

img
or img
This means that the angle 300 has sine equal to img.

Video Examples: Arcsine

Solved Example on Arcsine

Ques: arcsin(0.1218) = ?

Choices:

A. 120 
B. 830 
C. 780
D. 70
Correct Answer: D

Solution:

Step 1: arcsin(0.1218) = 70, rounded to the nearest degree. [Use calculator in degree mode.] 

Quick Summary

  • Arcsine returns the angle whose sine is a given number.
  • The domain of arcsine is [-1, 1].
  • The range of arcsine is [-π/2, π/2] radians or [-90°, 90°] degrees.
\[ x = \arcsin(y) \]

⚠️ Common Mistakes

  • Confusing arcsine with cosecant.
  • Forgetting to restrict the range of arcsine.
  • Using calculator in radian mode when degree mode is needed.

🌍 Real-World Uses

  • Calculating the launch angle of a projectile to hit a specific target, given the initial velocity and distance.
  • Determining the angle of elevation needed to point a telescope at a star, given the star's declination and the observer's latitude.
  • Designing the curvature of a road or railway to safely handle a specific speed, using the angle of banking.

📋 Standards Alignment

  • CCSS.MATH.HSF.TF.B.6
  • CCSS.MATH.HSF.TF.C.7

🔗 Related Links

🍎 Teacher Insights

Emphasize the restricted range of arcsine to ensure students understand it returns a specific angle within that range.

🎓 Prerequisites

  • Sine function
  • Inverse functions
  • Unit circle

Check Your Knowledge

Q1: arcsin(0.5) = ?

Q2: What is arcsin(1)?

Frequently Asked Questions

Q: What is the domain of arcsine?
A: The domain of arcsine is [-1, 1].

Q: What is the range of arcsine?
A: The range of arcsine is [-π/2, π/2] radians or [-90°, 90°] degrees.

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