Answer:
∴35.97 mg caffeine would be left in the system after 5 hours.
Step-by-step explanation:
Given that,
A cup of coffee has approximately 310 mg of caffeine.
Caffeine decrease at a rate 35% per hour.
Exponential Function:

y(t)= Amount caffeine after t hours
= Initial amount of caffeine
r= rate of decrease
t = Time in hour.
Here y(t)=?,
= 310 mg, r=35%=0.35, t= 5 hours

=35.97 mg
∴35.97 mg caffeine would be left in the system after 5 hours.
Answer:
A cardioid
Step-by-step explanation:
A cardioid is a curve in the shape of a heart traced by a point on the circumference of a circle as it rolls around a fixed circle of the same radius.
The equation of vertical cardioid is
± 
Given the polar curve is
4 
This is an equation of vertical cardioid.
So, it represents a cardioid.
Answer:
Option D!
Step-by-step explanation: