INTRODUCTORY EXERCISES

(3) Write the equation for the parabolas.

 (a) vertex (0,0), passing through (1,12) and symmetric about the axis x = 0

 (b) vertex (2,0), symmetric about the x-axis and passing through (3,2)

 (a) y - 0 = A(x - o)2

     y = Ax2

    12 = A(1)2 ==> A = 12

     y = 12x2


 (b) x - 2 = A(y - 0)2

     x - 2 = Ay2

     3 - 2 = A(2)2

     1 = 4A  ==>  A = 1/4


     x - 2 = y2/4

     x = y2/4 + 2