Option 21 DHS 5.2

EDS - 5.2
№1.21 Prove that the functions f (x) = √4 + x - 2; φ (x) = 3x as x → 0 are infinitesimal of the same order of smallness.
№2.21 Find the limits.
№3.21 Investigate these functions for continuity and build their graphs.
№4.21 Investigate these functions for continuity at the specified points. f (x) = ....; x1 = 2; x2 = 3.