JEE Main2013MathematicsApplication of DerivativesActual
Let f(1)=-2 and f^ (x) 4.2 for 1 x 6 . The possible value of f(6) lies in the interval :
Options
- A[15,19)
- B(- , 12)
- C[12,15)
- D[19, )
Correct answer
D. [19, )
Step-by-step solution
Given f(1)=-2 and f^ (x) 4.2 for 1 x 6 Consider f^ (x)= f(x+h)-f(x) h f(x+h)-f(x)=f^ (x) h (4.2) h So, f(x+h) f(x)+(4.2) h put x=1 and h=5 , we get f(6) f(1)+5(4.2) f(6) 19 Hence f(6) lies in [19, )