Find the standard form of the equation of the parabola with a focus at (0, -9) and a directrix y = 9

Question

lieutenantgeneral · Answer

Reorder the terms: 
y = -9 + 2x 

Solving 
y = -9 + 2x 

Solving for variable 'y'. 

Move all terms containing y to the left, all other terms to the right. 

Simplifying 
y = -9 + 2x
-2x+y=-9 
2x-y=9

Standard form is when all the variables are on the same side and there are no fractions, so in this case, we move the 2x 

y=2x - 9 
Subtract 2x from both sides 

The final answer is -2x + y = -9