For some reason I think it’s 60 but hopefully I’m right?! シ
Answer:
x = -1 <--- axis of symmetry
(-1, -9) <-- vertex
2, -4 (or, in my old precalc class we wrote our roots as (2,0) and (-4,0)) <--- roots
Step-by-step explanation:
a) Axis of symmetry equation is defined as
= x (i memorized this)
Quadratic equation form:
And our original equation:
So..
So our axis of symmetry is at x = -1,
b) now vertex point can be found by plugging this value back into our original equation.
y = 
y = 1 - 2 - 8
y = - 9
So our vertex is at (-1, -9)
c) Finally, lets factor
= 0 (when finding the roots, set y = 0, because we are trying to find where we cross the x-axis)
= 0
x = 2; x = -4 <--- Roots
perimeter ≈ 18.9 units ( to 1 dec. place )
Calculate the lengths of the 3 sides using the distance formula
d = √( (x₂ - x₁ )² + (y₂ - y₁ )²
with (x₁, y₁ ) = A(1, 1) and (x₂, y₂ ) = B(9, 2 )
d = √( (9 - 1 )² + (2 - 1 )² ) = √(64 + 1 ) = √65
repeat with (x₁, y₁ ) = B(9, 2) and (x₂, y₂ ) = C(4,5 )
d = √( (4 - 9 )² + (5 - 2 )² ) = √(25 + 9 ) = √34
let (x₁, y₁ ) = A(1, 1 ) and (x₂, y₂ ) = C(4, 5 )
d = √( (4 - 1 )² + (5 - 1 )² ) = √(9 + 16 = √25 = 5
perimeter = √65 + √34 + 5 ≈ 18.9 units
The answer is 25/3 or in decimal 8.333333
Assuming that the meteor crater forms a hemisphere, the formula for the surface area of the crater would be 2(pi)(radius^2). Set the crater equal to the formula for a hemisphere and substitute pi for 22/7 and you’d get 9687 = 2(22/7)(radius^2). Do some quick magic on the calculator to simplify and you end up with about 60,889.71 = radius^2. Take the square root from both sides and you get 246.8 when rounded. That should be the length of the radius, and so to find the diameter, just multiply that by 2 to get 493.5. Now I don’t really know what shape you mean by meteor crater, so we’re just assuming here that you mean half of a sphere, or a hemisphere. Don’t know if this is what you’re looking for, so good luck.
