Question

1) Define onto function. 2) Find k if f.f(k) = 5 where f (k) = 2k – 1​

Answer 1

Answer:

3

Step-by-step explanation:

2k-1=5

>2k=5+1=6

>k=3

Answer 2

Answer:

1)

An onto function is a function where it's range is the term in that function.

${ \sf{if \: function \: is \: x \: to \: y}} \\ { \sf{then \: range \: of \: function \: is \: y}} \\ i.e \: \: f(x) = y$

It is given by formula:

${ \boxed{ \sf{ {x}^{y} - {}^{x} c _{1}(n - 1) {}^{y} + {}^{x} c _{2} (x - 2) {}^{y} + ..... {x}^{n} }}}$

2).

$f(k) = 2k - 1 \\ but \: f(k) = 5 \\ 2k - 1 = 5 \\ 2k = 1 + 5 \\ 2k = 6 \\ k = 3$