Question

Can someone help me to find a vertex of parabola???

y=4x^2 + 4x -5

Answer 1

\[\text{the technique to find to vertex of the probola given it's standard equation
}\\ \text{y=ax^2+bx+c is called completing the square}\]

Answer 2

not the way i do it

Answer 3

so you need to complete the square for y=4x^2+4x-5

Answer 4

@satellite73 you mean u use calculus?

Answer 5

@Savannah_Lynn13 hey there interested to do this?

Answer 6

HI!!

Answer 7

no he use `-b/2a` formula :D

Answer 8

first coordinate of the vertex is always \(-\frac{b}{2a}\) and if you know the first coordinate you find the second by substitution

Answer 9

no he use `-b/2a` formula :D to find x-coordinate of the vertex and then substitute all x's for its value into the equation to find y-coordinate :P

Answer 10

here we have \(a=4,b=4\)
put in in to \[\huge-\frac{b}{2a}\] to get the \(x\) value of the vertex

Answer 11

well that's if he he knows that (-b/2a, f(-b/2a) ) is the vertex

Answer 12

ok so the thing i plug in would be -1/2, correct?

Answer 13

yes

Answer 14

yes x=-1/2
you need f(-1/2) too

Answer 15

i prefer the other way which show where thing come from
it is okay to use x=-b/2a as long as you know where it comes from

Answer 16

i though @satellite73 meant to take first derivative lol
when he not the way i do it

Answer 17

I think I skipped class that day

Answer 18

hahah lol

Answer 19

still need help
i guess you know thee answer

Answer 20

oh completing the square

Answer 21

so i get to\[y=4(-\frac{ 1 }{2})^2+4(-\frac{ 1 }{ 2 })-5\]

and no i don't know the anwer

Answer 22

it is arithmetic from here on in

Answer 23

what is \(\left(-\frac{1}{2}\right)^2\)?

Answer 24

yeah and i have a very difficult time with math, so for some reason this is really confusing me

Answer 25

if you don't know, i will tell you, but it is easy to square a fraction, square the top and the bottom

Answer 26

-1/4

Answer 27

no, when you square the minus sign goes away

Answer 28

\[\left(-\frac{1}{2}\right)^2=\left(-\frac{1}{2}\right)\times\left(-\frac{1}{2}\right)=\frac{1}{4}\]

Answer 29

now we are at \[y=4(\frac{ 1 }{4})+4(-\frac{ 1 }{ 2 })-5\]

Answer 30

you good from there?

Answer 31

is it -6?

Answer 32

Is this correct?

Answer 33

http://hotmath.com/hotmath_help/topics/vertex-of-a-parabola.html

Answer 34

y=4x^2 + 4x -5
y = 4(x^2 + x) -5
y = 4(x+1/2)^2 -4(1/4) -5
y = 4(x + 1/2)^2 - 6

vertex point = (-1/2, -6)

Answer 35

Thank you :)

Answer 36

you need to convert the equation into vertex form as mentioned in that web page. hope it helps