approximate using the trapezoidal rule by dividing the interval 1

Question

approximate using the trapezoidal rule  by dividing the interval 1<x<5 into four sub intervals.

∫6/x from 5 to 1

watchmath · Answer

Hi, if you divide the interval into 4 subintervals each sub interval is of length one.
Now the value of the function at 1,2,3,4,5 are 6,3,2,3/2,6/5.
For example for the trapezoid on top of the first interval, the area is (6+3)/2 * 1 = 9/2.
Do the same thing for the other sub intervals and add them all at the end to approximate the integral.

anonymous · Answer

i did that but got the wrong answer

anonymous · Answer

actually i see the mistake thanks i was multiplying by two instead of a half lol silly mistake thanks for pointing it out:)

watchmath · Answer

glad it works for you :). Should you need any help when I am not around you can ask me here: http://www.ask.watchmath.com

anonymous · Answer

thanks heaps ur  champ :)