The interest is $453.60.
The total amount includes principal + interest. The principal was 630 and the total amount was 1083.60.
1083.60 - 630 = 453.60.

Let's find the equivalent expressions ~
#1. PROBLEM



#2. PROBLEM



The maxima of f(x) occur at its critical points, where f '(x) is zero or undefined. We're given f '(x) is continuous, so we only care about the first case. Looking at the plot, we see that f '(x) = 0 when x = -4, x = 0, and x = 5.
Notice that f '(x) ≥ 0 for all x in the interval [0, 5]. This means f(x) is strictly increasing, and so the absolute maximum of f(x) over [0, 5] occurs at x = 5.
By the fundamental theorem of calculus,

The definite integral corresponds to the area of a trapezoid with height 2 and "bases" of length 5 and 2, so

