SOLUTION: Find the length and width of a rectangle whose area is 2x^2 +5x + 7

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Question 558845: Find the length and width of a rectangle whose area is 2x^2 +5x + 7
Answer by heilok(4) About Me  (Show Source):
You can put this solution on YOUR website!
The question is WRONG.

as this is a quadratic equequation,we have to consider the value of delta.

Delta=b^2-4ac
=5^2-4(2)(7)
=25-56
=-31<0.
So, there are no real roots for the equation, which is impossible for length.
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation ax%5E2%2Bbx%2Bc=0 (in our case 2x%5E2%2B5x%2B7+=+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=%285%29%5E2-4%2A2%2A7=-31.

The discriminant -31 is less than zero. That means that there are no solutions among real numbers.

If you are a student of advanced school algebra and are aware about imaginary numbers, read on.


In the field of imaginary numbers, the square root of -31 is + or - sqrt%28+31%29+=+5.56776436283002.

The solution is

Here's your graph:
graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B5%2Ax%2B7+%29