Find the particular solution that satisfies the given initial condition
Table of contents
- 0. Functions4h 53m
- 1. Limits and Continuity2h 2m
- 2. Intro to Derivatives1h 33m
- 3. Techniques of Differentiation2h 18m
- 4. Derivatives of Exponential & Logarithmic Functions1h 16m
- 5. Applications of Derivatives2h 19m
- 6. Graphical Applications of Derivatives6h 0m
- 7. Antiderivatives & Indefinite Integrals48m
- 8. Definite Integrals4h 36m
- 9. Graphical Applications of Integrals1h 43m
- 10. Integrals of Inverse, Exponential, & Logarithmic Functions21m
- 11. Techniques of Integration2h 7m
- 12. Trigonometric Functions6h 54m
- Angles29m
- Trigonometric Functions on Right Triangles1h 8m
- Solving Right Triangles23m
- Trigonometric Functions on the Unit Circle1h 19m
- Graphs of Sine & Cosine46m
- Graphs of Other Trigonometric Functions32m
- Trigonometric Identities52m
- Derivatives of Trig Functions42m
- Integrals of Basic Trig Functions28m
- Integrals of Other Trig Functions10m
- 13: Intro to Differential Equations2h 23m
- 14. Sequences & Series2h 8m
- 15. Power Series2h 19m
- 16. Probability & Calculus45m
13: Intro to Differential Equations
Separable Differential Equations
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Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
The scent of a certain air freshener evaporates at a rate proportional to the amount of the air freshener present. Half of the air freshener evaporates within 2 hours of being sprayed. If the scent of the air freshener is undetectable once 80% has evaporated, how long will the scent of the air freshener last?
A
t=1hr
B
t=2hrs
C
t=4.64hrs
D
t=1.83hrs

1
Step 1: Recognize that the problem describes exponential decay, where the rate of evaporation is proportional to the amount of air freshener present. The general formula for exponential decay is given by: , where is the initial amount, is the decay constant, and is time.
Step 2: Use the information that half of the air freshener evaporates in 222 hours to find the decay constant . Substitute and into the formula: . Simplify to solve for .
Step 3: Simplify the equation from Step 2 by dividing both sides by , then take the natural logarithm of both sides to isolate . The equation becomes: . Solve for .
Step 4: Use the decay constant to determine the time it takes for 80% of the air freshener to evaporate. If 80% has evaporated, then 20% remains, so . Substitute this into the formula: . Simplify to solve for .
Step 5: Simplify the equation from Step 4 by dividing both sides by , then take the natural logarithm of both sides to isolate . The equation becomes: . Substitute the value of from Step 3 to find the time.
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Multiple Choice
Separable Differential Equations practice set
