Limit
Definition
The value that a function f(x) approaches as the input x approaches a particular value. Written as lim(x→a) f(x) = L. It is the foundational concept of Calculus and is essential for defining derivatives and integrals.
Example
"lim(x→2) (x² − 4)/(x − 2) = lim(x→2)(x+2) = 4. Direct substitution would cause 0/0, but the limit still exists and equals 4."