AP EAMCET201823 Apr 2018Morning ShiftMathematicsDefinite IntegrationActual
If a and b are positive integers such that b>a , then _ n [ 1 n a + 1 n a+1 + 1 n a+2 + + 1 n b ]=
Options
- A( b a )
- B( a b )
- C(a b)
- D(a+b)
Correct answer
A. ( b a )
Step-by-step solution
The given limit aligned & _ x [ 1 n a + 1 n a+1 + 1 n a+2 + + 1 n b ] & = _ x [ 1 n a + 1 n a+1 + 1 n a+2 + + 1 n a+n(b-a) ] & = _ x _ r=0 ^ (b-a) n 1 n a+r = _ x 1 n _ r=0 ^ (b-a) n 1 a+ r n & = ₀^ (b-a) d x a+x & =[ (a+x)]₀^ b-a = (a+b-a)- (a+0) & = b- a= b a aligned