Question

Is this a valid mathematical sentence?\[\rm f:3\mapsto 9 ~where~f(x) = x^2 \]

Answer 1

i can read it, so its prolly not ;)

Answer 2

Is this a better way to write it?\[\rm f:x\mapsto x^2 \implies f:3\mapsto9 \]

Answer 3

nope

Answer 4

That's invalid notation.\[(f=x\mapsto x^2)\implies(f(3)=9)\]

Answer 5

f:{3} to {9}, x maps to x^2 is a function definition (to which u may sometimes add the codomain as well).

Answer 6

any function is defined over sets
if you enclose the 3 and 9 in parenthesis and say
"this set is my domain and the other one is my co-domain", then its fine

Answer 7

it can also be f(x) = 3x
we can write in many ways
we can not derive a function from a single relation

Answer 8

What I want to write is:

3 maps to 9 in the function f(x) = x^2

Answer 9

What'd be a rather good way to do so?

Answer 10

write f(3)=9

Answer 11

No, I'm trying to use much of the mapping symbol to get the hang of it.

Answer 12

f:{3}->{9} such that f(x)=x^2

Answer 13

Use Arrow Diagram

Answer 14

f: Set to ( arrow) Set, x maps to (arrow with tail) f(x) defines a function.

Answer 15

?

Answer 16

So\[\rm f:3\mapsto9|f(x) = x^2\]