SOLUTION: My problem is I don't know how to read the answer given in a Quadratic graph example, Where the curve cuts the x axis, the answer was about 4.37, -1.37, or Where the curve and li

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: My problem is I don't know how to read the answer given in a Quadratic graph example, Where the curve cuts the x axis, the answer was about 4.37, -1.37, or Where the curve and li      Log On


   

Question 629142: My problem is I don't know how to read the answer given in a Quadratic graph example, Where the curve cuts the x axis, the answer was about 4.37, -1.37,
or Where the curve and line cross read the x value about 5.54 and -0.54.
Ok I can understand an example that shows where a parabola cuts the x axis at 2 points say 3 and -3, I just don't understand where the 2 extra numbers are coming from in something like 5.54 and -0.54? I would be guessing thinking say 5.54 I would first go to 5.5 on the x axis? I'm guessing its read 5.5 being halfway between 5 and 6, but where does the 4 come from? or in the first examples where does the 7 come from?
Thanks
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi, 

Might recommemnd downloading the FREE graph software at http://www.padowan.dk.com to check your work

y= x^2-3x-6 and y= 2x-3

(Yes on the x-intercepts for the Parabloa) PLOT points (4.37,0) and (-1.37,0)

  x%5E2-3x-6+=+2x-3   || when the line and parabola intersect!

  x^2 -5x - 3= 0

x+=+%285+%2B-+sqrt%28+37%29%29%2F%282%29+

Yes,   x = 5.54  or x = -.54  and y = 8.08  or y = -4.08

line and parabola intersect at (5.54,8.08)  and (-.54,-4.08)

idea is for the second set were the x-values of the intersection:

y-values found by substituting x's into y = 2x-3

 y+=++2%2A5.54+-+3+=+8.08+  and y+=+2%2A-.54+-+3+=+-4.08

you have the Plotting idea correctly...do: over 5.54 up 8.08 PLOT Point

  and back .54 and down -4.08 PLOT Point