Mathematics > Standard Multiple Choice
Read the following SAT test question and then click on a button to select your answer.
The function f is graphed in the x y-plane above. If the function g is defined by function g of x = function f of x + 4, for how many values of x between negative 5 and 15 does function g of x equal 0?
(A) None
(B) One
(C) Two
(D) Three
(E) More than three
The correct answer is C
Explanation
The graph of the function g is the same as the graph of the function f translated up 4 units. The function f intersects the x-axis three times, but if the graph is shifted up 4 units, then the graph will intersect the x-axis only twice. Therefore, function g of x is equal to 0 for exactly two values of x between negative 5 and 15.