MHT CET202311 May 2023Evening ShiftMathematicsFunctionsActual
For all real x , the minimum value of 1-x+x^2 1+x+x^2 is
Options
- A0
- B1
- C1 3
- D3
Correct answer
C. 1 3
Step-by-step solution
aligned & f(x)= 1-x+x^2 1+x+x^2 & f^ (x)= (1+x+x^2 )(-1+2 x)- (1-x+x^2 )(1+2 x) (1+x+x^2 )^2 = & (-1+2 x-x+2 x^2-x^2+2 x^3 ) (1+x+x^2 )^2 = & -2+2 x^2 (1+x+x^2 )^2 aligned If f ^ (x)=0 , then -2+2 x^2 (1+x+x^2 )^2 =0 x^2=1 x= 1 f (x) at x=1 is 1 3 and f (x) at x=-1 is 1 , Minimum value of f (x) is 1 3 .