On a supply and demand graph you would see that the supply would meet the demand at the central point creating a secure system. However, this could change for the better or worse, compared to how "popular" the item is in the market.
Hello,
Adding the 2 equations,
x+y+x-y=k+k ==>2x=2k==>x=k
if x=k, y=k-k=0
solution is (k,0)
a. The 
component tells you the particle's height:
b. The particle's velocity is obtained by differentiating its position function:
so that its velocity at time 
is
c. The tangent to 
at is
The answer is 243 for the question above
