Answer:
Sin 90 = 1/1 = 1
Use trigonometry formula and a triangle with lengths of 1
Answer:

Step-by-step explanation:
Set up the equation:
Since C(t) gives the number of cars purchased in the t-th year after 1998, then make the number of cars equal to 15 000 and solve for t - the year:
20t^2 = 15000
t^2 = 750
t = 
The year will be simply 1998 + 5 \sqrt{30}
-16y = -12x + 48
y = .75x -3
The rate of change is .75 or 3/4.
Answer:
63/100
Step-by-step explanation: