
<u>Step-by-step explanation:</u>
Use the formula y = A cos (Bx - C) + D where
- A = amplitude
- Period = 2π/B
- Phase Shift = C/B
- D = vertical shift (aka midline)
Given: Max = 8, Min = 2, (1/2)Period = 20 → Period = 40
Amplitude (A) = (Max - Min)/2
= (8 - 2)/2
= 6/2
= 3
Midline (D) = (Max + Min)/2
= (8 + 2)/2
= 10/2
= 5
Period = 2π/B
→ B = 2π/Period
= 2π/40
= π/20
Notice that the Minimum touches the y-axis (not the Max) so there is no phase shift but there is a reflection → C-value = 0 & A-value is negative
Now, let's put it all together:
A = -3, B = π/20, C = 0, D = 5

Wait what does the question say 4 me it's blurry
Answer:
y+2=-4(x-1)
Step-by-step explanation:
y-y1=slope(x-x1)
just plug in the numbers you were given and youre good to go
Answer:

Step-by-step explanation:
The Law of Cosines works for any triangle and is given by:
, where
,
, and
are the sides of the triangle and
is the angle opposite to
.
In the given triangle, assign the variables:
Substituting these variables, we have:

We have two equations d=55t and d=20g
The left sides of this equations are the same than the right sides are equal too
a) 55t=20g
b) g=(55/20)t
c) t=6h => g=(55/20) *6 = 165/10=16.5 gallons
d= 55t= 55*6=330 miles or d=20g=20*16.5=330 miles
Good luck!!!