Glossary
Denominator
The expression or function located below the division bar in a fraction or rational expression.
Example:
In the limit , is the denominator.
Derivatives
The instantaneous rate of change of a function, representing the slope of the tangent line to the function's graph at a given point, found using specific differentiation rules.
Example:
To apply L'Hôpital's Rule, you must correctly find the derivatives of both the numerator and the denominator, such as knowing that the derivative of is .
Indeterminate Forms
Expressions that arise when directly substituting a value into a limit, such as 0/0 or ±∞/∞, which do not immediately reveal the limit's true value and require further analysis.
Example:
When trying to find , direct substitution results in , which is an indeterminate form.
L'Hôpital's Rule
A powerful theorem used to evaluate indeterminate limits of the form 0/0 or ±∞/∞ by taking the derivatives of the numerator and denominator separately.
Example:
To evaluate , we can apply L'Hôpital's Rule to get .
Limits
The value that a function approaches as its input approaches a certain value, a foundational concept in calculus for understanding function behavior.
Example:
The entire purpose of L'Hôpital's Rule is to evaluate challenging limits that initially appear indeterminate.
Numerator
The expression or function located above the division bar in a fraction or rational expression.
Example:
In the limit , is the numerator.
Quotient Rule
A fundamental differentiation rule used to find the derivative of a function that is the ratio of two differentiable functions, distinct from L'Hôpital's Rule.
Example:
If you need to find the derivative of , you would use the Quotient Rule, not L'Hôpital's Rule, as it's a derivative problem, not a limit evaluation.