Question

If f(x + 3) = f(x + 1) + 4r + 12 4x and f(0) = 2, then what is f(400) ?​

Answer 1

Given, f(x+f(x))=4f(x)   & f(1)=4

Substituting  X=1 we get f(1+f(1))=4f(1)⇒f(1+4)=16⇒f(5)=16

Now substitute x=5,  f(5+f(5))=4f(5)⇒f(5+16)=64=f(21)