we have the function
f(x)=6/(7x)
the interval [2,6]
Divide into fur rectangles
the width of each rectangle is equal to
(6-2)/4=1
the intervals are
(2,3) (3,4) (4,5) and (5,6)
using the right endpoints
the approximate area is equal to
A1=f(3)*(1)=[6/(7*3)]*(1)=6/21
A2=f(4)*(1)=[6/(7*4)]*(1)=6/28
A3=f(5)*(1)=[6/(7*5)]*(1)=6/35
A4=f(6)*(1)=[6/(7*6)]*(1)=6/42
therefore
the approximate area is
A=(6/21)+((6/28)+(6/35)+(6/42)
simplify
A=(6/7)*[(1/3)+(1/4)+(1/5)+(1/6)]
A=(6/7)*[(20+15+12+10)/60]
A=(6/7)*[57/60]
A=57/70 unit2 -----> exact answer