MHT CET202123 Sep 2021Evening ShiftMathematicsApplication of DerivativesActual
If x=-2 and x=4 are the extreme points of y=x^3- x^2- x+5 , then
Options
- A=3, =24
- B=-24m =-3
- C=-3, =-24
- D=24 , =3
Correct answer
A. =3, =24
Step-by-step solution
aligned & y=x^3- x^2- x+5 & d y d x =3 x^2-2 x- aligned We have x =-2 and x =4 as extreme points. aligned & ( d y d x )_ x=-2 =3(-2)^2-2 (-2)- =0 & 12+4 - =0 4 - =-12 & ( d y d x )_ x=4 =3(4)^2-2 (4)- =0 & 48-8 - =0 8 + =48 aligned Solving eq. (1) and (2), we get =3, =24