kČ = infinity * infinity = infinity
1/k = 0, because divide through infinity gives 0
sin (0) = 0
sinČ (o) = 0Č = 0
0 * kČ = 0 * infinity = NOT DEFINED
If your statement is directed at me, I usually try to do the weird abstract method that is easier but harder to see. But when I am beaten to it I show the more commonly known method such as L'hopital's. Substitution in limits can be a foreign concept to most high schoolers/college students so I showed this method to highlight how the limit is probably meant to be solved in their class or hwo to apply a known theorem.