Identify the vertex for the graph of y = −3x^2 + 6x − 4.

(1, 5)
(1, −1)
(−1, −13)
(−1, −9)

Question

Identify the vertex for the graph of y = −3x^2 + 6x − 4.

(1, 5)
 (1, −1)
 (−1, −13)
 (−1, −9)

nolegirl24 · Answer

@dude

dude · Answer

To find the vertex we use the equation
$x=\large \frac{-b}{2a}$

nolegirl24 · Answer

I thought so!! but i got x= -0.5 after i solved

dude · Answer

Not quite, check your math

$\large\frac{-(6)}{2\times (-3)}$

nolegirl24 · Answer

Oh i accidentally got the numbers mixed up

dude · Answer

Ah its okay haha

nolegirl24 · Answer

x = 1 right?

dude · Answer

Right, so we can eliminate C and D

dude · Answer

To find the y-value we substitute 1 back into the equation

$y = −3(1)^2 + 6(1) − 4$

nolegirl24 · Answer

okay so i got 
y = 3^2 + 6 - 4
y = 9 + 6 - 4
y = 15 - 4
y = 11

dude · Answer

You made a common mistake
Well I know anything times 1 is itself but you are supposed to follow PEMDAS

$y = −3(1)^2 + 6(1) − 4$

You are supposed to do $1^2$ first
giving you  $y = −3 + 6 − 4$

(Also watch your signs, -3)

nolegirl24 · Answer

y = -1?

dude · Answer

Right

dude · Answer

$(1,-1)$ is your answer

nolegirl24 · Answer

Okay so i had it before i just mixed up the A and B.

dude · Answer

Yes