It is different because to find out the answer, change all denominators to 10, since the LCD is 10.
6/10-5/10=1/10
6/10-6/10=0/10
1/10 is not equal to 0/10
The answer is D.
18/6=x;x
3*8=24
Yes, f(x)=0 is a single-term polynomial.
However, its degree is undefined because of the 0.
I assume your question amounts to finding the period of f(t)=8sin(4 pi t). A period L is a positive number such that f(t+L)=f(t) for all t. Since sin(x) is 2 pi perodic we can find the least number L such that 4pi(t+L)=4*pi*t+2*pi. Multiplying out we get
4pi(t+L)=4*pi*t+4*pi*L and we want to find L such that we get 4*pi*t+2*pi, notice if we take L=1/2 we get the desiered result 4*pi*t+4*pi*1/2=4*pi*t+2*pi. This proves that L=1/2 and your function has a period of 1/2.