How do I find the axis of symmetry in the below functions?

3(x + 4)^2 + 1
and
2x^2 −16x + 15

Would the axis of symmetry in the first one be 4?

Question

How do I find the axis of symmetry in the below functions?

3(x + 4)^2 + 1
and 
2x^2 −16x + 15

Would the axis of symmetry in the first one be 4?

anonymous · Answer

or -4?

amoodarya · Answer

y=a(x-b)^2+c

x=b is axis of symmetry

anonymous · Answer

How would I find the axis of symmetry in 2x^2 −16x + 15 though?

anonymous · Answer

-b/2a?

amoodarya · Answer

ok 
turn it to standard form

anonymous · Answer

It is in standard form.

anonymous · Answer

Would it be 16 / 4? Would the axis of symmetry in 2x^2 −16x + 15  be 4?

anonymous · Answer

And the axis of symmetry in 3(x + 4)^2 + 1 is -4 correct?

amoodarya · Answer

$$2x^2 −16x + 15 =2(x^2-8x) +15$$

$$2(x^2 −8x) + 15=2((x-4)^2 -4^2 )+15$$

amoodarya · Answer

3(x + 4)^2 + 1 is -4 
yes it is correct

anonymous · Answer

And the one in standard form is 4. Correct?

cybershadow · Answer

in the standard form it wud be x= -b/2a

anonymous · Answer

I pointed that out, but he put it in the y = form anyways xD

cybershadow · Answer

-(-16)/2x2 = 16/4 = 4 YES correct

anonymous · Answer

Yay, thanks!

cybershadow · Answer

u r on a roll tongiht haha well done!

anonymous · Answer

i can't give both of you medals. ):

amoodarya · Answer

yes for second x=4 is ok

amoodarya · Answer

"CyberShadow' 
I don't know that she knew derivation

cybershadow · Answer

haha no worries, I dont Care abt medalss xD lol

cybershadow · Answer

i got ur point Sir @amoodarya  nice explanation :)