You can
put this solution on YOUR website! Give f(x)=5x^2-3x+1, find f(-2).
f(x) = 5x² - 3x + 1
Replace all the x's on both sides with empty
parentheses:
f( ) = 5( )² - 3( ) + 1
Now fill in all the empty parentheses with -2
f(-2) = 5(-2)² - 3(-2) + 1
Leave the left side as it is but simplify the
right side:
f(-2) = 5(-2)² - 3(-2) + 1
f(-2) = 5(4) + 6 + 1
f(-2) = 20 + 7
f(-2) = 27
So you see, functional notation merely amounts
to "plugging in" for x what's in the parentheses
after the "f".
Edwin
