Point Slope Formula: y-y₁=m(x-x₁)
Linear Standard Form: Ax+By=C
Slope Intercept: y=mx+b
Notice how on both sides of the equation there is one coefficient (number being multiplied by x) and a constant (just a plain number). You want all constants to be on one side and all coefficients on the other. He’s how do to that:
2x+14=-21-5
I am choosing that all constants will be on the right side, so I will do the inverse operation of any constant on the left side to remove it. Here, a constant on the left side is 14. I will subtract 14 from both sides of the equation. Positive 14 minus 14 is zero, so it cancels out and removes it.
2x+14-14 = -21-5x
2x = -35-5x
See how the 14 is now gone? The equation looks much simpler now. Okay next, you can see that there is a coefficient on the “constant side” that I’ve chosen, so I am going to remove that. Negative 5 plus positive 5 equals zero. Do this on both sides of the equation.
2x+5x = -35-5x+5x
7x = -35
Now the equation is just two numbers. All that is left to do is divide by the last coefficient, 7, in this case.
7x/7 = -35/7
x = -5
Refer to the diagram shown.
At an arbitrary point P (x,y) on the parabola, the distance from the focus should be equal to the distance from the directrix.
The distance of P from the focus is
d₁ = √[x² + (y+3)²]
The distance from P to the directrix is
d₂ = 3 - y
Therefore
d₁ = d₂.
That is,
x² + (y+3)² = (3 - y)²
x² + y² + 6y + 9 = 9 - 6y + y²
x² + 12y = 0
y = - (1/12) x²
Answer: