SOLUTION: how do i find the vertex of y=x^2+4x+5

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Question 689719: how do i find the vertex of y=x^2+4x+5
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The x-coordinate of the vertex is at +-b%2F%282a%29+
when the equation is in the form +y+=+a%2Ax%5E2+%2B+b%2Ax+%2B+c+
In your case,
+y=x%5E2%2B4x%2B5+
+a+=+1+
+b+=+4+
+-b%2F%282a%29+=+-4%2F%282%2A1%29+
+-b%2F%282a%29+=+-2+
So now you know the vertex is at (-2,y)
To find +y+, plug +x+=+-2+
into the equation
+y+=+%28-2%29%5E2+%2B+4%2A%28-2%29+%2B+5+
+y+=+4+-+8+%2B+5+
+y+=+1+
The vertex is at (-2,1)
Here's a plot of the equation:
+graph%28+400%2C+400%2C+-7%2C+3%2C+-2%2C+10%2C+x%5E2+%2B+4x+%2B+5+%29+