Answer:
D
Step-by-step explanation:
From any point (x, y) on the parabola the focus and directrix are equidistant
Using the distance formula
= | y + 1 |
Squaring both sides
(x + 5)² + (y - 5)² = (y + 1)^2 , that is
(y + 1)² = (x + 5)² + (y - 5)² ← subtract (y - 5)² from both sides
(y + 1)² - (y - 5)² = (x + 5)² ← expand left side and simplify
y² + 2y + 1 - y² + 10y - 25 = (x + 5)²
12y - 24 = (x + 5)² ← factor left side
12(y - 2) = (x + 5)² ← divide both sides by 12
y - 2 = 
(x + 5)² ← add 2 to both sides
y = (x + 5)² + 2
or
f(x) = (x + 5)² + 2 → D
Answer:
Step-by-step explanation:
Hello!
Since Trey pays a flat monthly $6 fee, we can subtract that from the total bill:
$12.27 - $6 = $6.72
That leaves us with a total of $6.72 paid for minutes. We are told that Trey is charged 8 cents per minute of usage. Using the information above, we can create the following equation:
$0.08 x (minutes) = $6.72
Now divide $0.08 from both sides of the equation and simplify:
x (minutes) = 
minutes = 84
We have now proven that Trey was billed for 84 minutes.
I hope this helps!
Always when division with fractions, always move the decimal to the left.
Ok, a fun hack
if f⁻¹(a)=b then f(b)=a
so if f⁻¹(7)=b then f(b)=7
to find b, find x such that f(x)=7
7=0.5(3)^x
times both sides by 2 (or divide both sides by 0.5)
14=3^x
take log₃ of both sides
