022 Exam 2 Sample B, Problem 6

Find the area under the curve of  $y=6x^{2}+2x$ between the $y$-axis and $x=2$.

Foundations:
For solving the problem, we only require the use of the power rule for integration:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \int x^n dn = \frac{x^{n+1}}{n+1} + C}
For setup of the problem we need to integrate the region between the x - axis, the curve, x = 0 (the y-axis), and x = 2.

 Solution:

Step 1:
Set up the integral:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \int_0^{\,2} 6x^2 + 2x \,dx.}

Step 2:
Using the power rule we have:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \begin{array}{rcl} \int _0^2 6x^2+2x \,dx &=& 2x^3+x^2 \Bigr|_0^2 \\ \end{array}}

Step 3:
Now we need to evaluate to get:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 2x^3 + x^2 \Bigr|_0^2 = (2(2)^3+(2)^2)-(0+0) = 20.}

Final Answer:
Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle 20}

Return to Sample Exam