Question

Find the domain of the function f: R-->R defined by f(x)=C (c is constant)​

Answer 1

Answer:

4

f(x+y)−kxy=f(x)+2y

2

f(x+y)=f(x)+2y

2

+kxy

Put x=1,y=1⟹f(1+1)=f(1)+2+k⟹k=4

Put x=1,f(1+y)=f(1)+2y

2

+4(1)y=2(y+1)

2

⟹f(y)=2y

2

f(x+y).f(

x+y

1

)=2.(x+y)

2

.2(

x+y

1

)

2

=4