find the area of each of the region bounded by the following curves. write your solutions on the space…

find the area of each of the region bounded by the following curves. write your solutions on the space provided and sketch the bounding curves on graphing papers.\n1. $y = 4 - x^{2}$ and the line $y = x$

find the area of each of the region bounded by the following curves. write your solutions on the space provided and sketch the bounding curves on graphing papers.\n1. $y = 4 - x^{2}$ and the line $y = x$

Answer

Explanation:

Step1: Find intersection points

Set $4 - x^{2}=x$. Rearrange to $x^{2}+x - 4=0$. Using the quadratic formula $x=\frac{-b\pm\sqrt{b^{2}-4ac}}{2a}$ with $a = 1$, $b=1$, $c=-4$, we have $x=\frac{-1\pm\sqrt{1^{2}-4\times1\times(-4)}}{2\times1}=\frac{-1\pm\sqrt{17}}{2}$.

Step2: Set up integral for area

The area $A$ between two curves $y = f(x)$ and $y = g(x)$ is $A=\int_{a}^{b}|f(x)-g(x)|dx$. Here, $f(x)=4 - x^{2}$ and $g(x)=x$, and $a=\frac{-1-\sqrt{17}}{2}$, $b=\frac{-1 + \sqrt{17}}{2}$. So $A=\int_{\frac{-1-\sqrt{17}}{2}}^{\frac{-1+\sqrt{17}}{2}}((4 - x^{2})-x)dx$.

Step3: Integrate

$\int((4 - x^{2})-x)dx=4x-\frac{1}{3}x^{3}-\frac{1}{2}x^{2}+C$.

Step4: Evaluate definite - integral

$A=\left[4x-\frac{1}{3}x^{3}-\frac{1}{2}x^{2}\right]_{\frac{-1-\sqrt{17}}{2}}^{\frac{-1+\sqrt{17}}{2}}$ [ \begin{align*} &=\left(4\times\frac{-1 + \sqrt{17}}{2}-\frac{1}{3}\left(\frac{-1+\sqrt{17}}{2}\right)^{3}-\frac{1}{2}\left(\frac{-1+\sqrt{17}}{2}\right)^{2}\right)-\left(4\times\frac{-1-\sqrt{17}}{2}-\frac{1}{3}\left(\frac{-1-\sqrt{17}}{2}\right)^{3}-\frac{1}{2}\left(\frac{-1-\sqrt{17}}{2}\right)^{2}\right)\ &=\frac{17\sqrt{17}}{6} \end{align*} ]

Answer:

$\frac{17\sqrt{17}}{6}$