SOLUTION: Does this parabola open upward or downward? How do you know? y=x^2-1

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Does this parabola open upward or downward? How do you know? y=x^2-1      Log On


   

Question 618930: Does this parabola open upward or downward? How do you know?
y=x^2-1
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Upward, because the sign of the +x%5E2+ term
is positive.
here's the plot of +y+=+x%5E2+-+1+
+graph%28+400%2C+400%2C+-5%2C+5%2C+-2%2C+6%2C+x%5E2+-+1+%29+
----------------------------------------------
Here's the plot of +y+=+-x%5E2+-+1+
+graph%28+400%2C+400%2C+-5%2C+5%2C+-6%2C+2%2C+-x%5E2+-+1+%29+