Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
If
f
(
x
+
y
)
=
f
(
x
)
f
(
y
)
f(x+y) = f(x)f(y)
f
(
x
+
y
)
=
f
(
x
)
f
(
y
)
and
∑
x
=
1
∞
f
(
x
)
=
2
\sum_{x=1}^{\infty} f(x) = 2
∑
x
=
1
∞
f
(
x
)
=
2
,
x
,
y
∈
N
x, y \in \mathbb{N}
x
,
y
∈
N
, where
N
\mathbb{N}
N
is the set of all natural numbers, then the value of
f
(
4
)
f
(
2
)
\frac{f(4)}{f(2)}
f
(
2
)
f
(
4
)
is :
Browse the problem library