Let g x = ∫ 0 x f t d t , where f is continuous function in [ 0 , 3 ] such that 1 3 ≤ f t &#8804…

Let gx=0xftdt, where f is continuous function in [0,3] such that 13ft1 for all t[0,1] and 0ft12 for all t(1,3].

The largest possible interval in which g(3) lies is :

  1. -1,-12
  2. -32,-1
  3. 13,2
  4. [1,3]

Solution

13ft1t0,1

0ft12t(1,3]

Now, g3=03ftdt=01ftdt+13ftdt

0113dt01ftdt011.dt  ...1

and 130dt13f1dt1312dt  ...2

Adding, we get

13+0g31+123-1

13g32

Asked in: JEE Main 2021 (18 Mar Shift 2)

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