Given f ( x ) = 2 + 3x - x^{2 } and g ( x ) = 2 x -1 evaluate ( f + g ) ( 4)
Solution
Through evaluate we mean one of two things based on what is in the parenthesis. If there is a number in the parenthesis then we desire a number. If there is an x (or no parenthesis, as that implies & x) then we will carry out the operation and simplify as much as possible.
( f + g ) ( 4) = f ( 4) + g ( 4)
= (2 + 3( 4) - 4^{2} ) + (2 + 4( -1)
= -2 + 7
= 5