If the Midpoint Rule is used on the interval [,] with n subintervals, at what x-coordinates is the integrand evaluated?

This question is incomplete, the complete question is;

If the Midpoint Rule is used on the interval [ -1, 11 ] with n = 3 subintervals, at what x-coordinates is the integrand evaluated?

the x-coordinates are; [1, 5, 19]

Step-by-step explanation:

Given that;

interval = [ -1, 11 ]

interval length = [( 11 + 1 ) / 3] = 4

so intervals are; [ -1, 3 ]  [ 3, 7 ]  [7, 11 ]

now midpoints for the intervals are the x-coordinates

[ (1 + 3) / 2 ] = 1

[ (3 + 7) / 2 ] = 5

[ (7 + 11) / 2 ] = 19

therefore the x-coordinates are; [1, 5, 19]

not only in mathematics, scientific proof also are required in the other field of science. also maths proofs are of particular structure, containing steps and logics. so proving is like doing science, it is science. that's why it is important to prove. 

an inaccurate proof leads to errors, or stating results that are not accurate.  which wil mess the probelm up you dont want this