JEE Main2005MathematicsApplication of DerivativesActual
A function is matched below against an interval where it is supposed to be increasing. Which of the following pairs is incorrectly matched? Interval Function
Options
- A(- , ) x^3-3 x^2+3 x+3
- B[2, ) 2x^3-3 x^2-12 x+6
- C(- , 1 3 ] 3 x^2-2 x+1
- D(- , -4] x^3+6 x^2+6
Correct answer
C. (- , 1 3 ] 3 x^2-2 x+1
Step-by-step solution
Clearly function f(x)=3 x^2-2 x+1 is increasing when f^ (x)=6 x-2 0 x [1 / 3, ) Hence (C) is incorrect.