Question

f:R->R defined by f(x)=2x+3 then fof(x)= *

Answer 1

Answer :

fof(x) = 4x + 9

Solution :

• Given : f : R → R , f(x) = 2x + 3
• To find : f(x) = ?

We have ;

f(x) = 2x + 3

Thus ,

=> fof(x) = f [ f(x) ]

=> fof(x) = f (2x + 3)

=> fof(x) = 2(2x + 3) + 3

=> fof(x) = 4x + 6 + 3

=> fof(x) = 4x + 9

Hence ,

fof(x) = 4x + 9