# Further calculus

posted by
**Alison** on
.

1) A price p (in dollars) and demand x for a product are related by

2x^2+6xp+50p^2=10600.

If the price is increasing at a rate of 4 dollars per month when the price is 30 dollars, find the rate of change of the demand.

2)

a) The price (in dollars) p and the quantity demanded q are related by the equation: p^2+2q^2=1100.

If R is revenue, dR/dt can be expressed by the following equation: dR/dt=A dp/dt,

where A is a function of just q.

b)Find dR/dt when q=20 and dp/dt=4.

Thanks in advance!