How do I find the area bounded by a function?

Question

Find the area bounded by f(x)=10-4x² and the x-axis on the interval [1,2] by finding the limit of the upper and lower sums. Find the width Δx=(b-a)/n, the lower heights f(a+(b-a)(i-1)/n) the lower sum ⁿ_i=1∑f(a+(b-a)(i-1)/n)Δx and then let n→∞. Find the upper heights f(a+(b-a)i/n) and the upper sum ⁿ_i=1Σf(a+(b-a)i/n)Δx and then let n→∞.

Answer 1