Approximating Areas With Riemann Sums Practice Test

The trapezoidal rule with $$n = 4$$ subintervals is used to approximate $$\int_2^6 \frac{1}{x} , dx$$. What is the value of $$\Delta x$$ and how many function evaluations are needed?

A right Riemann sum with $$n = 8$$ subintervals approximates $$\int_4^{12} (x^2 - 3x) , dx$$. The width of each subinterval is: