Question

ACT PREP Q/ PLEASE HELP: The functions f(x) = –(x + 4)^2 + 2 and g(x) = (x − 2)^2 − 2 have been rewritten using the completing-the-square method. Is the vertex for each function a minimum or a maximum? Explain your reasoning for each function.

Answer 1

@Nnesha @misty1212 @freckles

Answer 2

@iwanttogotostanford you there?

Answer 3

Let us first define a maximum or a minimum function. Maxima or minima is the relative extremas and they are determined by a function. Relative maximum have the highest point on a given function, a relative minimum has the lowest point or points on a given interval in a function.

Answer 4

@Zale101 yes1 sorry

Answer 5

Is the vertex at max or min in an upside down parabola?

Answer 6

max

Answer 7

@zale101

Answer 8

@Nnesha @freckles

Answer 9

@Vocaloid

Answer 10

please, I really need help like step by step :-) @Vocaloid

Answer 11

@peachpi

Answer 12

Like @zale101 said you need to look at the direction the parabolas open.

Answer 13

I need step by step I just want to learn because I need a study guide, i don't need to know how to do it now but could you just write it step by step because i am just studying for the ACT and i have a bunch more questions to go:-D

Answer 14

I'm not sure how that helps you. For one, there really is no step by step for this problem, and that will be the case for nearly every problem on the ACT. These problems are designed to be solved almost by inspection. You can either graph the equations or recognize that the sign of a tells you whether it opens up or down.

y =a (x - h)^2 +k
Positive a opens up, negative a opens down.
(h, k) is the vertex