Having been tutored by Nav for 3U and 4U was one of the best decisions I made in my HSC. Nav has a clear and concise way of explaining concepts far exceeding my teachers. For example one of my weakest topics was proofs as I was quite unfamilar with the logic required. In just two lessons I...
This will be my last post, BOS is literally the ultimate form of procrastinating. You feel as though you are doing work yet BOS is simply another form of social media. Its been a fun ride.
The reccurence relation is : C_{n+1}=C_{0}C_n+C_1C_{n-1}+...+C_nC_0 where C_{k} is the kth catalan number.
The general term is: C_n=\frac{1}{n+1}{2n\choose n}
where {2n \choose n} means 2n 'choose' n. It may be worthwhile looking into some basic combinatorics i.e. permutations and...
\cos{x}\cos{y}-\sin{x}\sin{y}=\frac{1}{4}(\sqrt{3}-\sqrt{2})-\frac{1}{4}(\sqrt{3}+\sqrt{2})
\cos(x+y)=-\frac{\sqrt{2}}{2}
x+y=\frac{3\pi}{4}
Since second quadrant.
The main reason is that you need to use transformers for a bunch of appliances (e.g. if your phone charger didn't have a transformer built into it, it is going to explode if it gets the 230V coming from the plug point). Transformers only work for AC current and not DC so of course AC is preferred.