How to rewrite an expression in the standard form of a complex number using i

The video tutorial explains how to simplify expressions using the imaginary unit 'i'. It begins by introducing the concept of 'i' and its necessity for handling square roots of negative numbers. The instructor demonstrates rewriting expressions with 'i' and applying rules of exponents. The process of simplifying square roots is detailed, including attempts to find the largest square number that divides evenly into a given number. The tutorial concludes with the realization that some expressions cannot be further simplified.

What steps did the teacher take to simplify sqrt(42)?

Explain why the square root of 42 cannot be simplified further.