23. Intro to Derivatives & Area Under the Curve

Find the area under the curve in the function below from $x=-4$ to $x=8$.

Find the area under the curve in the function below from $x=-2$ to $x=8$.

Use 3 rectangles to approximate the area under $f\left(x\right)=x^2$ from $x=2$ to $x=5$ with right endpoints. 

Use 6 rectangles to approximate the area under $f\left(x\right)=x^3$ from $x=0$ to $x=3$ with left endpoints.