8,000 x .80= 6,400
8,000-6,400= 1,600
1,600-1,000= 600 that is the amount of tuition she will need to pay each year.
Answer:
D. 1
Step-by-step explanation:
We have the expression, 
We get, eliminating the cosecant function,

As, sinx is reciprocal of cosecx and cosx is reciprocal of secx,
i.e. 
i.e. 
Since, we know that, 
Thus,

So, after simplifying, we get that the result is 1.
Hence, option D is correct.