Question

Find the line of symmetry for the parabola whose equation is y = 2x^2 - 4x + 1.

x = -1
x = 1
x = 2

Answer 1

\[x=-\frac{b}{2a}\]

Answer 2

if i knew how to do that i would haha

Answer 3

\[y=ax^2+bx+c\]
\[y=2x^2-4x+1\] what are \(a\) and \(b\) ?

Answer 4

a is 2 and b is 4

Answer 5

no

Answer 6

\(a=2\) is correct \(b=4\) is incorrect

Answer 7

hmm?

Answer 8

\[\large y=\color{red}ax^2+\color{blue}bx+c\]\[\large y=\color{red}2x^2\color{blue}{-4}x+1\]

Answer 9

tbh ima fail this class

Answer 10

yeah i guess
is it not clear that the minus sign comes with the number, so that \(a=2,b=-4\) ?

Answer 11

okay i get that now

Answer 12

then your last job is to compute \(-\frac{b}{2a}\) with \(a=2,b=-4\)

Answer 13

allright so it will be \[x= \frac{ -4 }{ 22}\]

Answer 14

\(2a\) means \(2\times 2\) not \(22\)

Answer 15

haha so it would b 4

Answer 16

also you forgot that \(b=-4\) and not \(4\)
yes the denominator is 4

Answer 17

\[x=-\frac{ 4 }{ 4 }\]
i hate algebra

Answer 18

\[\huge -\frac{\color{blue}b}{2\times\color{red}a}\]

Answer 19

\[\huge -\frac{\color{blue}{-4}}{2\times\color{red}2}\]

Answer 20

yeah i hate algebra too, but this is arithmetic actually

Answer 21

now the only question is, since we know \(2\times 2=4\)
what is
\[\large -\frac{-4}{4}\]

Answer 22

answer is 1

Answer 23

yes