Practice Introduction to Differential Equations in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

An equation that contains an unknown function and one or more of its derivatives. Solving a DE means finding the function(s) that satisfy the equation.

An algebraic equation like x2=4 asks 'what number satisfies this?' A differential equation like dydx=2x asks 'what function has this derivative?' The answer isn't a number but a family of functions: y=x2+C.

Showing a random 20 of 50 problems.

Example 1

easy
Is y=e−3x a solution of y′+3y=0?

Example 2

easy
What is the degree of (y′)3+y=x?

Example 3

challenge
Show that y=1x solves y′=−y2 and state where it is valid.

Example 4

medium
For exponential decay dydt=−0.5y, write the general solution.

Example 5

medium
Find the particular solution of dydx=1x with y(1)=0.

Example 6

hard
Solve the IVP y′=2xy, y(0)=3 by inspection (using y=Cex2).

Example 7

hard
Show that y=x2+Cx solves xy′+y=3x2 for any constant C.

Example 8

medium
How many arbitrary constants does the general solution of a 3rd-order DE have?

Example 9

medium
Solve the IVP dydx=ex, y(0)=2.

Example 10

easy
Is y=e2x a solution of y′=2y?

Example 11

medium
A bacteria population satisfies dPdt=0.2P with P(0)=50. Find P(t).

Example 12

medium
Find the general solution of y′′=6x.

Example 13

medium
Solve the IVP y′′=2, y(0)=1, y′(0)=3.

Example 14

medium
Solve the IVP dydx=6x2, y(1)=5.

Example 15

hard
Solve y′=y, y(0)=−2.

Example 16

easy
Write the DE that says 'the rate of change of y with respect to t is proportional to y.'

Example 17

medium
Determine the order of (d3ydx3)+sin⁡y=0.

Example 18

easy
Verify y=3e2x solves y′=2y, and find the particular solution with y(0)=5.

Example 19

hard
Find all r so that y=erx solves y′′+y′−6y=0.

Example 20

easy
Classify dydx=ky in words.