in 6:49 you could just factorise the numerator into (x+4)(x-4) difference of two squares so that the (x--4) terms cancel so you just have x+4, then you can substitute x=4 and get 8, similar thing in 8:50. but good video!
for those wondering yes you can divide by x-4 even though in the limit it says x->4 (4-4=0 so people might think this is division by 0) but remember x never reaches 4 it only approaches it, so its safe to cancel
Note: I meant approaching 0.
Indeed, it's a lifesaver.
in 6:49 you could just factorise the numerator into (x+4)(x-4) difference of two squares so that the (x--4) terms cancel so you just have x+4, then you can substitute x=4 and get 8, similar thing in 8:50. but good video!
for those wondering yes you can divide by x-4 even though in the limit it says x->4 (4-4=0 so people might think this is division by 0) but remember x never reaches 4 it only approaches it, so its safe to cancel
@@Akjjf6628 yes, you can definitely solve it by factoring and Thanks for the feedback!
Your video would be even better if you proved that rule :)
@@DirectedArt Thanks for the feedback!
@MathwithTenzin No worries, I just want the mathematics community to grow and be a great place to learn.