All Calculus 1 Resources
Example Questions
Example Question #2871 : Functions
The population of a town grows exponentially from to in . What is the population growth constant?
Exponential growth is modeled by the equation
where is the final amount, is the inital amount, is the growth constant and is time.
In this problem, , and . Substituting these variables into the growth equation the solving for gives us
Example Question #185 : Constant Of Proportionality
Cobalt-60 has a half-life of . What is the decay constant of Cobalt-60?
The half-life of an isotope is the time it takes for half the isotope to disappear. Isotopes decay exponentially.
Exponential decay is also modeled by the equation
where is the final amount, is the inital amount, is the growth constant and is time.
Since half the isotope has disappeared, the final amount is half the inital amount , or .
In this problem, .
Substituting these variables into the exponential equation and solving for gives us
Example Question #186 : Constant Of Proportionality
The number of cats double every . How many cats will there be after if there are cats initially?
Exponential growth is modeled by the equation
where is the final amount, is the inital amount, is the growth constant and is time.
After , the number of cats has doubled, or the final amount is double the inital amount , or .
In this problem, .
Substituting these variables into the exponential equation and solving for gives us
To find the number cats after year, , , and
Example Question #187 : Constant Of Proportionality
The number of students enrolled in college has increased by every year since . If students enrolled in , how many student enrolled in ?
The exponential growth is modeled by the equation
where is the final amount, is the inital amount, is the growth rate and is time.
In this problem, , , and . Substituting these values into the equation gives us
Example Question #188 : Constant Of Proportionality
The number of CD players owned has decreased by annually since . If people owned CD players in , how many people owned CD players in ?
The exponential growth is modeled by the equation
where is the final amount, is the inital amount, is the growth rate and is time.
In this problem, and . because the rate is decreasing. Substituting these values into the equation gives us
Example Question #189 : Constant Of Proportionality
You deposit into your savings account. After , your account has in it. What is the interest rate of this account if the account was untouched during the ?
The exponential growth is modeled by the equation
where is the final amount, is the inital amount, is the growth rate and is time.
In this problem, , and . Substituting these variables into the growth equation and solving for r gives us
Example Question #1081 : Rate
Find the direct constant of proportionality of from .
To find direct constant of proportionality , you need to find the slope of the line between the two points at and . To do so we use the formula:
Example Question #252 : Ap Calculus Bc
The rate of growth of the population of Reindeer in Norway is proportional to the population. The population increased from 9876 to 10381 between 2013 and 2015. What is the expected population in 2030?
We're told that the rate of growth of the population is proportional to the population itself, meaning that this problem deals with exponential growth/decay. The population can be modeled thusly:
Where is an initial population value, and is the constant of proportionality.
Since the population increased from 9876 to 10381 between 2013 and 2015, we can solve for this constant of proportionality:
Using this, we can calculate the expected value from 2015 to 2030: