pure maths
posted by marie .
use trapezium rule with 3 intervals to estimate the value of intergrating x=0 and x=3 squarerooting 1+xsquared

Did you make your diagram?
I read your question as estimating the definite integral of √(1+x^2) from 0 to 3
You should be looking at 3 trapezoids with a base width of 1 each and the heights for the values of x = 0,1,2,3 would be 1,√2,√5, and √10 respectively.
The estimated area would be
(1+√2)(1)/2 + (√2+√5)(1)/2 + (√5+√10)(1)/2
= (1/2)(1 + 2√2 + 2√5 + √10)
= 5.73
check my arithmetic.