Is there a shorter formula for trapezoidal rule? (1 Viewer)

[seilk5]

I remember the teacher taught us an easier method to do it rather than 2f(a+h), 2f(a+2h), etc when doing more than one intervals. Can someone post the formula? Cause my calculator can't fit all the working out especially when they usually ask for ten intervals...

 

[timinator1993]

for trap we use h/2( (y(0) + y(n)) + 2( y(1) + y(2) + (3) +..+y(n-1) ) )
Where h=(b-a)/n , and n is the number of trips.

 

[kangy93]

Hi there! To answer these ones, I have a method that works no matter how many intervals. I'll try to show through an example since it's easier that way:
e.g. If you get this table:
X 3 4 5 6 7 8
Y A B C D E F

1) Get the STRIP length. i.e. (4-3)/2
2) For the Y values, multiply EVERYTHING EXCEPT THE FIRST AND LAST (A and F) values by 2. i.e. --> A + 2(B+C+D+E) + F
3) Multiply 1) and 2)
Goodluck!

 

[amour]

edit: oops tis is simpsons