How do you evaluate the function $f (x) = 3x^2 + 3x -2$ for $f (a) + f (2)$ ?

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Answer 1 · 2015-11-27T07:25:21

$f(a) + f(2) = 3a^2 + 3a + 14$

When evaluating a function $f(x)$ at some specific value, you simply replace $x$ with that value wherever $x$ appears in the function.
So

$f(a) = 3a^2 + 3a - 2$

and

$f(2) = 3(2)^2 + 3(2) - 2 = 12+6-2 = 16$

Thus

$f(a) + f(2) = (3a^2 +3a - 2) + 16 = 3a^2 + 3a + 14$

How do you evaluate the function f (x) = 3x^2 + 3x -2f (x) = 3x^2 + 3x -2 for f (a) + f (2)f (a) + f (2)?