Math Problem Statement

Find the area bounded by the following curves and lines.

Find the area bounded by the curves y = 2sin(x) and y = sin(2x) over the interval 0 ≤ x ≤ π.

Solution

To find the area bounded by the curves y=2sinxy = 2\sin x and y=sin2xy = \sin 2x over the interval 0xπ0 \leq x \leq \pi, we follow these steps:

1. Set up the area integral:

The area between two curves is given by the integral:

Area=ab(f(x)g(x))dx\text{Area} = \int_a^b \left( f(x) - g(x) \right) dx

Here, f(x)=2sinxf(x) = 2\sin x (the upper curve) and g(x)=sin2xg(x) = \sin 2x (the lower curve). The limits of integration are from 00 to π\pi.

Thus, the area is:

Area=0π(2sinxsin2x)dx\text{Area} = \int_0^\pi \left( 2\sin x - \sin 2x \right) dx

2. Compute the integral:

We now compute the integral of each function separately:

0π2sinxdx=2[cosx]0π=2((1)(1))=2×2=4\int_0^\pi 2\sin x \, dx = 2 \left[ -\cos x \right]_0^\pi = 2 \left( -(-1) - (-1) \right) = 2 \times 2 = 4

For the second term:

0πsin2xdx=12[cos2x]0π=12(cos2πcos0)=12(11)=0\int_0^\pi \sin 2x \, dx = \frac{-1}{2} \left[ \cos 2x \right]_0^\pi = \frac{-1}{2} \left( \cos 2\pi - \cos 0 \right) = \frac{-1}{2} (1 - 1) = 0

3. Final answer:

The area is:

Area=40=4\text{Area} = 4 - 0 = 4

Thus, the area bounded by the curves y=2sinxy = 2\sin x and y=sin2xy = \sin 2x between 00 and π\pi is 4\boxed{4}.


Would you like more details on any step? Here are some related questions for further practice:

  1. What happens to the area if we integrate over a different interval?
  2. How does the area change if the upper curve is modified to y=3sinxy = 3\sin x?
  3. What is the area between y=cosxy = \cos x and y=sinxy = \sin x over the interval 0xπ/20 \leq x \leq \pi/2?
  4. How would you find the points of intersection between y=2sinxy = 2\sin x and y=sin2xy = \sin 2x?
  5. Can you generalize this method for any pair of sinusoidal functions?

Tip: When finding the area between curves, always make sure to carefully identify which curve is on top over the entire interval to avoid negative areas.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Integration
Area between curves
Trigonometric functions

Formulas

Area = ∫(f(x) - g(x)) dx
Integral of sin(x) = -cos(x)
Integral of sin(2x) = -(1/2)cos(2x)

Theorems

Fundamental Theorem of Calculus
Trigonometric Integrals

Suitable Grade Level

College-level Calculus