Given $f (x) = x - 4$ $f(x)=x-4$ , how do you find f(1)?

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Answer 1 · 2016-08-01T15:37:24

$f (1) = 1 - 4 = - 3$ $f(color(red)1) = color(red)1-4 = -3$

When the function starts as $f (x)$ $f(x)$ it means that the expression which follows has $x$ $x$ terms in it.

$f (1)$ $f(1)$ means that where there WAS an $x$ $x$ , there is NOW the value $1$ $1$ .

"Find, determine, evaluate, calculate" all mean just substitute the 1 in place of $x$ $x$ in the expression and work out the value.

$f (x) = x - 4$ $f(color(red)x) = color(red)(x)-4$

$f (1) = 1 - 4 = - 3$ $f(color(red)1) = color(red)1-4 = -3$

$f (2) = 2 - 4 = - 2$ $f(color(red)2) = color(red)2-4 = -2$

$f (5) = 5 - 4 = 1$ $f(color(red)5) = color(red)5-4 = 1$

$f (m) = m - 4$ $f(color(red)m) = color(red)m-4$ etc...

Given f(x)=x−4f(x)=x-4, how do you find f(1)?