What is the vertex of Y = -x^2 +2x +3

(0, 3)

(1, 0)

(1,4)

(4,1)

Question

What is the vertex of Y = -x^2 +2x +3

		
(0, 3)

		
(1, 0)

		
(1,4)

		
(4,1)

noelgreco · Answer

The x-coordinate of the vertex is found by:

$$x=\frac{ -b }{ 2a }$$

the front end of the quadratic formula.  The y-coordinate is found by simply plugging the x result in the original equation.

anonymous · Answer

I'm lost, can you explain more please? I got D as my answer

jim_thompson5910 · Answer

-x^2 +2x +3

is the same as

-1x^2 +2x +3

jim_thompson5910 · Answer

-1x^2 +2x +3

is in the form

ax^2 + bx + c

so that means

a = -1
b = 2
c = 3

jim_thompson5910 · Answer

Plug a = -1, b = 2 into

$$\large x=\frac{ -b }{ 2a }$$

to get x = ??

anonymous · Answer

Alright hold on hun

anonymous · Answer

I'm lost..

jim_thompson5910 · Answer

$$\large x=\frac{ -b }{ 2a }$$

$$\large x=\frac{ -2 }{ 2(-1) }$$

$$\large x=?$$

anonymous · Answer

This is like another language hun.. Is there another way to solve it?

jim_thompson5910 · Answer

what is 2(-1) equal to

jim_thompson5910 · Answer

"2(-1)" means "2 times -1" btw

anonymous · Answer

Oh!  thank you!

jim_thompson5910 · Answer

what is x? were you able to find it?

anonymous · Answer

Yes

jim_thompson5910 · Answer

x = ??

jim_thompson5910 · Answer

I'm just making sure you have the right answer

anonymous · Answer

i got (1,4)

jim_thompson5910 · Answer

good

here's the graph to confirm

anonymous · Answer

Thank you

jim_thompson5910 · Answer

you're welcome