This should be simple but I can't get to the right answer.
Q) Using the trapezium rule with 3 ordinates, find an estimate for the area under the curve y = x^2 - 3x from x = 4 to x = 8.
If there are 3 ordinates, you do 4 (8-4) divided by 3 right? I think that's where I'm going wrong. Then input 4+1.333 and the answer of that + 1.333 as my middle ordinates then x=4 and x=8 as my end points, so I get:
4 + 2(12.44 + 24.44) + 40 giving me 117... the answer is apparently 80.