Chapter 6: Problem 75
A region \(\mathcal{R}\) is described. Calculate its area. $$ \begin{aligned} &\mathcal{R} \text { is the region that is bounded above by } y=\pi x / 2 \text { and }\\\ &\text { below by } y=\arcsin (x) \text { for } 0 \leq x \leq 1 \end{aligned} $$
Short Answer
Expert verified
The area of region \( \mathcal{R} \) is \( 1 - \frac{\pi}{4} \).
Step by step solution
01
Identify the Functions
The region \( \mathcal{R} \) is bounded above by the line \( y = \frac{\pi x}{2} \) and below by the curve \( y = \arcsin(x) \). We will compute the area between these two curves.
02
Set Up the Integral for Area
The area \( A \) of region \( \mathcal{R} \) between the two curves from \( x = 0 \) to \( x = 1 \) is given by the integral \[ A = \int_{0}^{1} \left( \frac{\pi x}{2} - \arcsin(x) \right) \, dx \].
03
Integrate the Function
Calculate the integral \[ \int_{0}^{1} \frac{\pi x}{2} \, dx \] which equals \( \frac{\pi}{2} \left[ \frac{x^2}{2} \right]_{0}^{1} = \frac{\pi}{4} \).
04
Integrate the Second Function
Calculate the integral of \( \arcsin(x) \) with respect to \( x \), which equals \[ \int_{0}^{1} \arcsin(x) \, dx = x \arcsin(x) + \sqrt{1-x^2} + C \bigg|_{0}^{1} = \frac{\pi}{2} - 1 \].
05
Compute the Area
The area \( A \) is then \( \frac{\pi}{4} - (\frac{\pi}{2} - 1) = 1 - \frac{\pi}{4} \).
06
Simplify the Result
Thus, the area of the region \( \mathcal{R} \) is given by \( 1 - \frac{\pi}{4} \) which approximates to approximately \( 0.215 \).
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Understanding Definite Integrals
Definite integrals are a fundamental concept in calculus that allow us to calculate the accumulation of quantities, like finding the area under a curve. The primary goal of using a definite integral is to evaluate a function over a specific interval. In simple terms, it helps us to measure the space between the curve (or line) and the horizontal x-axis within the interval we are considering.
Let's delve deeper into this:
Let's delve deeper into this:
- The limits of integration tell us the interval over which we are finding the area. In this case, the interval is from 0 to 1.
- The integral symbol \( \int \) represents the process of integration—adding up infinite small pieces to find the total.
- The result gives a number representing the accumulated change, in this scenario, the area between the curves.
Calculating Area Between Curves
The area between curves is a classic applications of definite integrals. In this context, it helps us determine the region between two given functions over a certain interval. The exercise you encountered requires calculating the area of a region \( \mathcal{R} \) that is bounded by the curves \( y = \frac{\pi x}{2} \) on top and \( y = \arcsin(x) \) at the bottom.
Here’s how this works:
Here’s how this works:
- First, recognize which function is on top (here, \( y = \frac{\pi x}{2} \)) and which is below (here, \( y = \arcsin(x) \)).
- The area \( A \) is computed by subtracting the lower function from the upper function, then integrating over the given interval.
- The integral expression \( \int_{0}^{1} \left( \frac{\pi x}{2} - \arcsin(x) \right) \, dx \) is set up to calculate this difference in height across the entire range from 0 to 1.
Exploring Trigonometric Functions
Trigonometric functions, like \( \arcsin \), play a crucial role in various mathematical computations, especially involving curves and angles. In our exercise, the functional form \( y = \arcsin(x) \) describes part of the boundary of region \( \mathcal{R} \). Understanding how these functions behave is vital for accurate problem solving.
Some key insights about \( \arcsin(x) \):
Some key insights about \( \arcsin(x) \):
- \( \arcsin(x) \) is the inverse function of \( \sin(x) \), which means it tells us the angle whose sine is \( x \).
- This function is defined for \( x \) values between -1 and 1, ensuring the result is a real number.
- In the context of calculus, \( \arcsin(x) \) is significant due to its non-linear shape and its integration properties.