Learning goals: Teacher Facing Comprehend that the symbol $\sqrt{x}$ denotes only the positive square root of $x$. Explain why equations of the form $x^2 = a$ can have two solutions, while equations of the form $\sqrt{x} = a$ cannot have more than one solution. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from Alg2.3 Complex Numbers and Rational Exponents, Algebra 2.