Answer:
z = 3
Step-by-step explanation:
Since the points are collinear then the slopes between the points are equal.
Calculate the slope m using the slope formula
m =
with (x₁, y₁ ) = P (2, - 3) and (x₂, y₂ ) = Q (3, - 2)
m = = 1
Repeat with
(x₁, y₁ ) = Q (3, - 2) and (x₂, y₂ ) = R (8, z )
m = =
, then
= 1 ( multiply both sides by 5 )
z + 2 = 5 ( subtract 2 from both sides )
z = 3
Answer:
Part 1) The directrix of the parabola is y=-4.25
Part 2) The focus of the parabola is F(1,-3.75)
Step-by-step explanation:
we have
This is a vertical parabola open upward
we know that
If a parabola has a vertical axis, the standard form of the equation of the parabola is
where
p≠ 0
The vertex of this parabola is at (h, k).
The focus is at (h, k + p).
The directrix is the line y = k - p.
The axis is the line x = h.
step 1
Convert the equation of the parabola in standard form
so
----> equation in standard form
The vertex is the point (1,-4)
4p=1 ------> p=1/4
step 2
Find the directrix of the parabola
The directrix is the line y = k - p
we have
k=-4
p=1/4
substitute the values
y = k - p
y=-4-(1/4)=-17/4
y=-4.25
step 3
Find the focus of the parabola
we know that
The focus is at (h, k + p).
we have
h=1
k=-4
p=1/4
substitute
F(1,-4+1/4)
F(1,-3.75)