Skip to main content
Mathovia

Math Practice

Limit Laws Practice Problems

Use the rules of limits to split each limit into pieces, or substitute directly when the function allows it. Watch the denominator: if its limit is 0, the quotient law doesn’t apply.

Written by
MPhil in Mathematics, Founder of Mathovia
Published

Mathematics verification: Mathematical formulas, calculations, worked examples and solutions are reviewed for accuracy before publication. How we check our work

Limit Laws Practice Problems

These problems follow the limit laws lesson. Each one can be solved with the rules of limits and direct substitution, apart from the last few, which test when a law can’t be used.

The laws in one line each

  • Sum and difference: the limit of is .
  • Constant multiple and product: constants factor out, and the limit of is .
  • Quotient: the limit of is , only if .
  • Power and root: limits pass through powers and roots, as long as the root is defined.

Common mistakes to watch for

  • Using the quotient law when the bottom goes to 0. Check the denominator limit first.
  • Reading as an answer. Simplify, then substitute again.
  • Splitting limits that do not exist. Each piece needs a limit for the laws to apply.
  • Forgetting the root law needs a defined root. An even root needs a non-negative inside.

Frequently Asked Questions

Can I just substitute every time?+

Substitution works for polynomials, and for rational functions, roots, trig and exponential functions where they are defined. If it gives 0/0, simplify first; if it gives a nonzero number over 0, the limit does not exist.

How do I enter a fraction?+

Type a decimal such as 1.6 or a fraction such as 8/5. Both are accepted.

More practice problems