23:18 tutorial3 Tutorial 3 Vraag 1. Question 1. Bercken die limiet indien dit bestaan of toon aan dat die Find the limit if it exists or show that the limit of the fol- limiet van die volgende funksies nie bestaan nie: lowing functions does not exist: a) lim(z,y)-+(3,-1)(17 + y' ) = b) lim(z,y)-+(0,0) / (1, y) = lim(z,y)-+(0.0) -493 c) lim(z,y)-+(0,0) f(x, y) = lim(z,y)-+(0.0) de ty 23 sin(4y) = Vraag 2. Question 2. 2.0. a) Hoekom is f(z, y) = nie kontinu in die punt 2.0. Justify why f(x, y) = 1 is not continuous at the (0, 0). point (0, 0). b) Hoekom is die funksie f(r, y) = ysin(x + y) differensieer- | Why is the function f(r, y) = ysin(r+y) differentiable in the baar in die punt (0, #)? Bereken fr(0, ) en fy(0, =) en point (0, =)? Find fr(0, 5) and fy(0, #) and use a theorem gebruik 'n stelling om jou uitspraak te staaf. to prove your claim