Math Problem Statement

Karjakin

Calculate the integral \( \int_0^5 f(x) \, dx \) for the piecewise function \( f(x) \) given by: \[ f(x) = \begin{cases} x & \text{if } 0 \leq x < 1 \\ 1 & \text{if } 1 \leq x \leq 3 \\ x - 4 & \text{if } 3 < x \leq 5 \end{cases} \]

Solution

To solve question 17, we need to calculate the integral of the piecewise function f(x)f(x) from x=0x = 0 to x=5x = 5 using appropriate geometric area formulas. The function f(x)f(x) is defined as follows:

x & \text{if } 0 \leq x < 1 \\ 1 & \text{if } 1 \leq x \leq 3 \\ x - 4 & \text{if } 3 < x \leq 5 \end{cases}$$ ### Step-by-Step Solution To evaluate $$\int_0^5 f(x) \, dx$$, we can split the integral based on the intervals defined by the piecewise function. #### 1. Integral from $$x = 0$$ to $$x = 1$$: On this interval, $$f(x) = x$$. $$\int_0^1 x \, dx = \left[ \frac{x^2}{2} \right]_0^1 = \frac{1^2}{2} - \frac{0^2}{2} = \frac{1}{2}$$ #### 2. Integral from $$x = 1$$ to $$x = 3$$: On this interval, $$f(x) = 1$$. $$\int_1^3 1 \, dx = \left[ x \right]_1^3 = 3 - 1 = 2$$ #### 3. Integral from $$x = 3$$ to $$x = 5$$: On this interval, $$f(x) = x - 4$$. $$\int_3^5 (x - 4) \, dx = \left[ \frac{x^2}{2} - 4x \right]_3^5$$ Calculating this: 1. Substitute $$x = 5$$: $$\frac{5^2}{2} - 4 \times 5 = \frac{25}{2} - 20 = \frac{25 - 40}{2} = \frac{-15}{2} = -7.5$$ 2. Substitute $$x = 3$$: $$\frac{3^2}{2} - 4 \times 3 = \frac{9}{2} - 12 = \frac{9 - 24}{2} = \frac{-15}{2} = -7.5$$ The integral over this interval is: $$-7.5 - (-7.5) = -7.5 + 7.5 = 0$$ ### Combining Results Now, we add up the results from each interval: $$\int_0^5 f(x) \, dx = \frac{1}{2} + 2 + 0 = \frac{1}{2} + 2 = 2.5$$ ### Final Answer $$\int_0^5 f(x) \, dx = 2.5$$ --- Would you like further details on this solution or have additional questions? Here are some related questions for further exploration: 1. How would the integral change if the interval was from $$x = 0$$ to $$x = 4$$? 2. Can we visualize the graph of $$f(x)$$ and interpret each integral as an area under the curve? 3. How does the piecewise nature of $$f(x)$$ affect the computation of the integral? 4. What is the interpretation of each interval’s contribution to the total area? 5. How would we approach integrating a more complex piecewise function with more intervals? **Tip:** For piecewise functions, break the integral into separate parts according to each interval and evaluate each segment individually before summing the results.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Integral Calculus
Piecewise Functions
Definite Integrals
Area Calculation

Formulas

Definite integral \( \int_a^b f(x) \, dx \)
Integral of linear functions \( \int x \, dx = \frac{x^2}{2} + C \)
Area under constant functions \( \int a \, dx = a(x - x_0) \)

Theorems

Fundamental Theorem of Calculus

Suitable Grade Level

Grades 11-12