Solution:
Given that,
[tex]y = f(x) = 9x[/tex]
We have to find f(x) when x = 1/2
We can solve by substituting x = 1/2 in given function
[tex]f(x) = 9x\\\\Plug\ in\ x = \frac{1}{2}\\\\f(\frac{1}{2}) = 9 \times \frac{1}{2}\\\\f(\frac{1}{2}) = 4.5[/tex]
Thus f(x) is equal to 4.5 when x = 1/2