Save
...
Unit 7: Differential Equations
7.7 Exponential Models with Differential Equations
Understanding exponential growth and decay models:
Save
Share
Learn
Content
Leaderboard
Share
Learn
Cards (63)
What is the formula for exponential growth?
y
=
y =
y
=
C
e
(
k
t
)
Ce^(kt)
C
e
(
k
t
)
What does the variable `y` represent in the exponential growth formula?
Quantity at time `t`
In exponential decay, the decay constant `k` must be positive.
True
The formula for exponential growth remains the same regardless of the quantity being modeled.
True
What is the formula for exponential decay?
y
=
y =
y
=
C
e
(
−
k
t
)
Ce^( - kt)
C
e
(
−
k
t
)
In the exponential decay formula, `k` is called the decay
constant
The differential equation for exponential growth is `dy/dt =
ky
`.
True
Match the differential equation with its model:
d
y
/
d
t
=
dy / dt =
d
y
/
d
t
=
k
y
ky
k
y
↔️ Growth
d
y
/
d
t
=
dy / dt =
d
y
/
d
t
=
−
k
y
- ky
−
k
y
↔️ Decay
In the decay model `
dy/dt
= -ky`, the constant `k` is positive.
True
Steps to calculate the growth/decay rate `k` for an exponential model:
1️⃣ Identify initial quantity `C` and final quantity `y` at time `t`
2️⃣ Use the formula for growth or decay to find `k`
What is the growth rate of a bacteria population that grows from 500 to 1200 in 3 hours?
0.29
What is the decay rate of a substance that reduces from 300 grams to 150 grams in 8 days?
0.087
What does the growth constant `k` represent in exponential growth?
Rate of increase
What is the formula for exponential decay?
y = Ce^(-kt)
What is the formula for a radioactive substance decaying at 5% per year if its initial mass is 100 grams?
y = 100e^(-0.05t)
The formula to find `k` for exponential decay is `k = (ln(y/C)) / t`.
False
A bacteria population grows from 500 to 1200 in 3 hours. What is the growth rate `k`?
0.29
The formula for exponential decay is `k = (ln(y/C)) / t`
False
What is the general solution for the differential equation `dy/dt = ky` in exponential growth?
y
=
y =
y
=
C
e
k
t
Ce^{kt}
C
e
k
t
What is the solution to the differential equation `dy/dt = -ky` for exponential decay?
y
=
y =
y
=
C
e
−
k
t
Ce^{ - kt}
C
e
−
k
t
Suppose a population starts at 100 cells and grows at 20% per hour. What is the expression for `y` at time `t`?
y
=
y =
y
=
100
e
0.2
t
100e^{0.2t}
100
e
0.2
t
What is the formula used to model population growth?
P
(
t
)
=
P(t) =
P
(
t
)
=
P
0
e
k
t
P_{0}e^{kt}
P
0
e
k
t
In the exponential growth formula, `C` represents the initial
quantity
In the exponential growth formula, `t` represents the time
elapsed
What does the variable `C` represent in the exponential decay formula?
Initial quantity
What does the variable `y` represent in the exponential growth formula?
Quantity at time `t`
The decay constant
`k`
in exponential decay must be positive.
True
What does the variable `y` represent in the exponential decay formula?
Quantity at time `t`
The differential equation for exponential decay is `dy/dt =
-ky
What do the differential equations for exponential growth and decay express?
Rate of change
What is the differential equation for a population growing at 2% per year if it starts at 1000?
dy/dt = 0.02y
For exponential growth, the formula to find `k` is `k = (ln(y/C)) /
t
The growth/decay rate is a percentage per unit
time
Exponential growth occurs when a quantity increases at a constant rate.
False
A bacteria population doubles every hour. What is the growth constant `k` for this scenario?
ln(2)
In the exponential decay formula `y = Ce^(-kt)`, the variable `C` represents the initial
quantity
Match the differential equation with its description:
`dy/dt = ky` ↔️ Growth
`dy/dt = -ky` ↔️ Decay
What formula is used to calculate the growth rate `k` if `y = Ce^(kt)`?
k = (ln(y/C)) / t
What is the differential equation for a population growing at 2% per year from an initial size of 1000?
d
y
d
t
=
\frac{dy}{dt} =
d
t
d
y
=
0.02
y
0.02y
0.02
y
What does `y` represent in the growth/decay rate formulas?
Final quantity
See all 63 cards
See similar decks
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
79 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
54 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
79 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
71 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
31 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
47 cards
Understanding exponential growth and decay models:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
71 cards
Solving exponential differential equations:
AP Calculus AB > Unit 7: Differential Equations > 7.7 Exponential Models with Differential Equations
32 cards
7.8 Exponential Models with Differential Equations
AP Calculus BC > Unit 7: Differential Equations
28 cards