Write an equation of a parabola with its vertex at the origin and its focus at (0,-6)

Umm.. just started this 2day and its not on my notes(p′︵‵。)

In triangle abc, the length of side ab is 12 cm, the length of side bc is 5 cm, and the length of side ca is 9 cm. find the measure of angle a using the law of cosines.

Aline has a slope of 1/4 and passes through point (0.4,-1/2). what is the value of the y-intercept?