SOLUTION: I have this quadratic equation and I can not figure it out; -0.2x squared + 12x + 11. I have to find the x and y coordinates. Help please.

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: I have this quadratic equation and I can not figure it out; -0.2x squared + 12x + 11. I have to find the x and y coordinates. Help please.      Log On


   

Question 287996: I have this quadratic equation and I can not figure it out; -0.2x squared + 12x + 11. I have to find the x and y coordinates. Help please.
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
Do you see an equal sign? I don't see an equal sign. So nothing is equated and so there is no equation.
-0.2x^2+12x+11
Which x and y coordinates do you want? There is no y.
Do you see a "y"?
You really should copy the problem as given and not try to invent it.
(x-60.9031) (x+0.903074) = 0
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case -0.2x%5E2%2B12x%2B11+=+0) has the following solutons:

x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca

For these solutions to exist, the discriminant b%5E2-4ac should not be a negative number.

First, we need to compute the discriminant b%5E2-4ac: b%5E2-4ac=%2812%29%5E2-4%2A-0.2%2A11=152.8.

Discriminant d=152.8 is greater than zero. That means that there are two solutions: +x%5B12%5D+=+%28-12%2B-sqrt%28+152.8+%29%29%2F2%5Ca.

x%5B1%5D+=+%28-%2812%29%2Bsqrt%28+152.8+%29%29%2F2%5C-0.2+=+-0.903074280724887
x%5B2%5D+=+%28-%2812%29-sqrt%28+152.8+%29%29%2F2%5C-0.2+=+60.9030742807249

Quadratic expression -0.2x%5E2%2B12x%2B11 can be factored:
-0.2x%5E2%2B12x%2B11+=+-0.2%28x--0.903074280724887%29%2A%28x-60.9030742807249%29
Again, the answer is: -0.903074280724887, 60.9030742807249. Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-0.2%2Ax%5E2%2B12%2Ax%2B11+%29