evaluate the following integral by interpreting it in terms of areas from drawing the graph of the function…

evaluate the following integral by interpreting it in terms of areas from drawing the graph of the function being integrated. $int_{-4}^{4}(3 - |x|)dx=$

evaluate the following integral by interpreting it in terms of areas from drawing the graph of the function being integrated. $int_{-4}^{4}(3 - |x|)dx=$

Answer

Explanation:

Step1: Analyze the function

The function (y = 3-\vert x\vert) can be written as (y=\begin{cases}3 - x, & x\geq0\3 + x, & x<0\end{cases}). It is a V - shaped graph with vertex at ((0,3)).

Step2: Split the integral by symmetry

Since (y = 3-\vert x\vert) is an even function ((f(-x)=f(x))), we can write (\int_{-4}^{4}(3 - \vert x\vert)dx = 2\int_{0}^{4}(3 - x)dx).

Step3: Use integral rules

We know that (\int_{0}^{4}(3 - x)dx=\int_{0}^{4}3dx-\int_{0}^{4}xdx). By the power - rule of integration (\int x^n dx=\frac{x^{n + 1}}{n+1}+C(n\neq - 1)) and (\int kdx=kx + C) ((k) is a constant), we have (\int_{0}^{4}3dx=3x\big|{0}^{4}=3\times4-3\times0 = 12) and (\int{0}^{4}xdx=\frac{x^{2}}{2}\big|{0}^{4}=\frac{4^{2}}{2}-\frac{0^{2}}{2}=8). So (\int{0}^{4}(3 - x)dx=12 - 8=4).

Step4: Calculate the original integral

Since (\int_{-4}^{4}(3 - \vert x\vert)dx = 2\int_{0}^{4}(3 - x)dx), then (\int_{-4}^{4}(3 - \vert x\vert)dx=2\times4 = 8).

Answer:

8