Mathematics > Standard Multiple Choice
Read the following SAT test question and then click on a button to select your answer.
In the xy-plane, the graph of the equation above assumes its maximum value at . What is the value of b?
(A) –8
(B) –4
(C) 4
(D) 8
(E) 10
The Correct answer is D.
Explanation
Choice (D) is correct. Since the graph of the quadratic equation 
assumes its maximum at 
, it can be written in the form 
, where 
is some constant. This representation is equivalent to 
, from which it follows that 
(and
).