1. ## function

If $f(x+y) = f(x\cdot y)$ and $x,y\geq 4$ and $f(8) = 9\;,$ Then $f(9) =$

My Trial Solution:: Given $f(x+y) = f(x\cdot y)$

Given $f(8) = f(4+4) = f(4\cdot 4) = f(16)$

Now $f(16) = f(8+8) = f(8\cdot 8) = f(64)$

Now How can I solve after that

Help me

Thanks

2. ## Re: function

Originally Posted by jacks
If $f(x+y) = f(x\cdot y)$ and $x,y\geq 4$ and $f(8) = 9\;,$ Then $f(9) =$

My Trial Solution:: Given $f(x+y) = f(x\cdot y)$

Given $f(8) = f(4+4) = f(4\cdot 4) = f(16)$

Now $f(16) = f(8+8) = f(8\cdot 8) = f(64)$

Now How can I solve after that

Help me

Thanks
weird little problem

9 = f(8) = f(4+4) = f(16)

f(9) = f(5+4) = f(20)

f(20) = f(16+4) = f(64)

f(64) = f(8*8) = f(8+8) = f(16)

f(9)= f(20)= f(64) = f(16) = f(8) = 9