i have a parabola has an equation y=12-x^2 . what is the specifications ?

Question

i am going to solve a problem which is my  college assignment?????? 

Answer 1

1. The parabola opens downward. (a<0)
2. The vertex is at point (0, 12)
3. The max. value in this function is {12}.
4. The axis of symmetry is y-axis.
5. What is the x- and y-intercepts?
    - for the x-intercept, we take the equation y = 12 - x² and set y to zero and solve for x.
       12 - x² = 0 ---> x² = 12 ---> x = ±√12 the graph crosses the x-axis at - √12 and +√12.
   - for the y-intercept, likewise, set the x at zero and solve for y. This gives us 12.