Limit Using Conjugates: Square Root Trick, Limit Using Conjugates Playlist

In this video, Prof. Happy Strawberry from the F.I.T. Department of Mathematics introduces a powerful new technique for limits: \lim_{x\to 4}\frac{\sqrt{x}-2}{x-4} We begin with direct substitution and again get the indeterminate form 0/0. But this time, factorization does not work. Instead, we use a key idea: Multiply by the conjugate We go step by step: * Identify the conjugate expression * Multiply numerator and denominator * Use the difference of squares * Cancel the common factor * Simplify and evaluate This is one of the most important techniques when square roots appear in limits.