Question

what is the axis of symmetry for f(x)=-2(x-4)^2+2

Answer 1

hmmm what's its vertex anyway?

Answer 2

axis of symmetry : x=h

y= -a(x-h)^2 +k

this formula sheet will help you set for life with basic conics
http://www.jfkcougars.org/ourpages/auto/2013/2/5/43231143/Conics-Formula-Sheet.pdf

Answer 3

yeah but i need help with the steps

Answer 4

step 1. find h

Answer 5

h=4

Answer 6

yes, axis of symmerty is 4

write as x=4

Answer 7

well... can you get the vertex off the equation... notice is in vertex form already http://www.mathwarehouse.com/geometry/parabola/images/standard-vertex-forms-thumb.png

Answer 8

so the vertex would be 4,2

Answer 9

yes, x of vertex is 4
x=4
is the equation of axis of symmetry

Answer 10

ok but how do i explain how i got that to my teacher.

Answer 11

i get that the answer is 4 but idk how to explain how i got it

Answer 12

I'd say something like
"When a vertical line runs through the center of the parabola, it divides the parabola into two symmetric halves. Such line is called axis of symmetry. Since we know that axis of symmetry is straight and vertical, it would have no slope. the equation would be x= a value. Now that we analyze the equation, the center is at (4,2). x=4 would be the only vertical line that runs through the vertex of the equation. Therefore this is the axis of symmetry of f(x)"

You can shorten it. It's lengthy and all in my words.

Answer 13

thank you so much! that was what i was looking for. you are a big help thank you (:

Answer 14

anytime :)