[f4 maths]Functions

1. Rewrite the algebraic expression –x^2 – 6x – 4 in the form of a(x-h)^2+ k by the method of completing the square, and hence find the vertex of the graph of the quadratic function y= –x^2 – 6x - 4
-x^2 - 6x -4
= -(x^2+6x+9) +9-5
= -(x+3)^2 +4
Hence vertex of the graph of y = -x^2 -6x -4 is (-3,4)

2006-11-13 10:53:47 補充：
Typing mistake: -x^2 - 6x -4 = -(x^2+6x+9) + 9 - 4= -(x+3)^2 + 5Hence vertex of the graph of y = -x^2 -6x -4 is (-3,5)