Math Problem Statement

find the area of the region enclosed between y=3sin(x) and y=2cos(x) from x=0 to x=0.5pi

Solution

To find the area enclosed between the curves y=3sin(x)y = 3\sin(x) and y=2cos(x)y = 2\cos(x) from x=0x = 0 to x=π2x = \frac{\pi}{2}, we need to follow these steps:

Step 1: Set up the integral

The area between two curves from x=ax = a to x=bx = b is given by the integral of the difference of the functions, where the upper function is subtracted from the lower function:

A=ab(f(x)g(x))dxA = \int_a^b \left( f(x) - g(x) \right) dx

In our case, f(x)=3sin(x)f(x) = 3\sin(x) and g(x)=2cos(x)g(x) = 2\cos(x), so the area can be written as:

A=0π2(3sin(x)2cos(x))dxA = \int_0^{\frac{\pi}{2}} \left( 3\sin(x) - 2\cos(x) \right) dx

Step 2: Compute the integral

We now integrate the expression:

A=0π23sin(x)dx0π22cos(x)dxA = \int_0^{\frac{\pi}{2}} 3\sin(x) \, dx - \int_0^{\frac{\pi}{2}} 2\cos(x) \, dx

We can compute each integral separately:

  1. For 3sin(x)dx\int 3\sin(x) \, dx, the antiderivative is 3cos(x)-3\cos(x).
  2. For 2cos(x)dx\int 2\cos(x) \, dx, the antiderivative is 2sin(x)2\sin(x).

Step 3: Evaluate the integrals

We evaluate the integrals from x=0x = 0 to x=π2x = \frac{\pi}{2}:

  1. [3cos(x)]0π2=3(cos(π2)cos(0))=3(01)=3\left[ -3\cos(x) \right]_0^{\frac{\pi}{2}} = -3\left(\cos\left(\frac{\pi}{2}\right) - \cos(0)\right) = -3(0 - 1) = 3
  2. [2sin(x)]0π2=2(sin(π2)sin(0))=2(10)=2\left[ 2\sin(x) \right]_0^{\frac{\pi}{2}} = 2\left(\sin\left(\frac{\pi}{2}\right) - \sin(0)\right) = 2(1 - 0) = 2

Step 4: Final computation

Now subtract the results:

A=32=1A = 3 - 2 = 1

Conclusion:

The area enclosed between y=3sin(x)y = 3\sin(x) and y=2cos(x)y = 2\cos(x) from x=0x = 0 to x=π2x = \frac{\pi}{2} is 1 square unit.


Would you like more details on any step or have any questions about the process?

Related Questions:

  1. How can you find the area between two curves when they intersect?
  2. How do you handle situations where the functions are not simple trigonometric functions?
  3. What happens if the integral gives a negative result? How do you interpret that in terms of area?
  4. How can you generalize the process for finding areas enclosed between more than two curves?
  5. What other methods exist for finding the area of irregular regions, such as numerical methods?

Tip:

When setting up integrals for areas between curves, always double-check which function is the upper function and which is the lower to ensure that you're subtracting correctly!

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Calculus
Definite Integrals
Area Between Curves
Trigonometric Functions

Formulas

A = ∫[a,b] (f(x) - g(x)) dx
Antiderivatives of sin(x) and cos(x)

Theorems

Fundamental Theorem of Calculus

Suitable Grade Level

Grades 11-12