Use three rectangles to approximate the area under the curve of $f\left(x\right)=3{(x-2)}^2$ from $x=0$ to $x=3$ using the midpoint rule.

Use five rectangles to estimate the area under the curve of $f\left(x\right)=x^2$ from $x=0$ to $x=5$ using left endpoints.

Use two rectangles to estimate the area under the curve of $f\left(x\right)=\frac{1}{2}{x}^2$ from $x=0$ to $x=3$ using left endpoints.

Use four rectangles to estimate the area under the curve of $f\left(x\right)=x^2+2$ from $x=0$ to $x=2$ using left endpoints.

Use three rectangles to estimate the area under the curve of $f\left(x\right)=\frac{1}{3}{x}^3$ from $x=0$ to $x=3$ using the right endpoints.

Estimate the value of the definite integral ${\int }_0^{10}f\left(x\right)dx$ using five subintervals and the left endpoint approximation, given that $f\left(x\right)=x^2$.

Estimate the value of the definite integral ${\int }_{-2}^{4}g\left(x\right)dx$ using six subintervals and the left endpoint approximation. Which of the following best describes the process?