MHT CET202312 May 2023Morning ShiftMathematicsFunctionsActual
If g (x)=1+ x and f ( g (x))=3+2 x +x , then f ( f (x)) is
Options
- Ax^2+4 x+6
- Bx^4+x^2+6
- Cx^2+x+6
- Dx^4+4 x^2+6
Correct answer
D. x^4+4 x^2+6
Step-by-step solution
aligned & g(x)=1+ x and f ( g (x))=3+2 x +x & f ( g (x))= [( x )^2+2 x +1 ]+2 & =( x +1)^2+2 & =[ g (x)]^2+2 & f (x)=x^2+2 & f ( f (x))= (x^2+2 )^2+2=x^4+4 x^2+6 & aligned