Question

A parabola has its axis of symmetry as the x axis. The parabola opens to the left, so its equation is of the type

• A. y² =4ax , a>0
• B. x²=4ay , a>0
• C. y² = - 4ax , a>0
• D. x²= -4ay , a>0

Answer 1

The correct option is C

y² = - 4ax , a>0

For a parabola which has x axis as the axis of symmetry, the equation has to be of the type _y² =4ax , a>0 or _y² = - 4ax , a>0.Moreover, if it opens to the left, then that clears the way and we get the answer _y² = - 4ax , a>0.