Question

Trapezoidal approximation check

Answer 1

I think the answer is 108000

Answer 2

@imranmeah91

Answer 3

@experimentX @TuringTest @KingGeorge

Answer 4

@dpaInc

Answer 5

Give me a minute.

Answer 6

I'm getting 2205, not 108000

Answer 7

Can you show me what you did?

Answer 8

Using the formula given on http://en.wikipedia.org/wiki/Trapezoidal_rule I calculated http://www.wolframalpha.com/input/?i=%2815%2F2%29*%2815+%2B+%2815%2B18%29%2B%2818%2B20%29%2B%2820%2B19%29%2B%2819%2B23%29%2B%2823%2B24%29%2B%2824%2B22%29%2B%2822%2B12%29%29

Answer 9

Since \(b-a=15\) for every interval, and you have to divide by 2, I was able to factor out a \(15/2\), and add all of the \(f(a)+f(b)\)

Answer 10

with n=4, your trapezoid's height will be 30 not 15. so you're only considering these intervals: [0, 30], [30, 60], [60, 90], and [90, 120].
add up the area of those 4 trapezoids should give you the trapezoidal approximation for n=4 of that f(x).