SOLUTION: Find the vertex of -0.2x^2+12x+11
I have used two different methods and came up with two different answers. I have solved for the x= 30 but when I went to do the maximum value I
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-> SOLUTION: Find the vertex of -0.2x^2+12x+11
I have used two different methods and came up with two different answers. I have solved for the x= 30 but when I went to do the maximum value I
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Question 487841: Find the vertex of -0.2x^2+12x+11
I have used two different methods and came up with two different answers. I have solved for the x= 30 but when I went to do the maximum value I used two solutions and that is where I came up with different answers. The first I substituted the 30 in to the equation -0.2(30)^2+12(30)+11= 191; on the second I used the formula 4ac-b^2 /4a with a= -0.2 b= 12 c=11 I got 4(-0.2)(11)-12^2 divided by 4(-0.2) and came to the answer 169. Found 2 solutions by John10, nerdybill:Answer by John10(297) (Show Source):
You can put this solution on YOUR website! y =191 is the correct result.
For the second formula, you used the wrong formula for y:
The correct one is y = c - (b^2)/4a = 11 - (12^2)/4(-0.2) = 11 - (-180) = 11 + 180 = 191 which is what you are looking for.
John10:)
You can put this solution on YOUR website! Find the vertex of -0.2x^2+12x+11
the x-value of the vertex:
x = -b/(2a)
x = -12/(2*(-0.2))
x = -12/(-0.4)
x = 30
.
y-value of vertex:
-0.2x^2+12x+11
-0.2(30)^2+12(30)+11
-0.2(900)+12(30)+11
191
.
vertex is at (30, 191)
