In interval notation, when is demand price greater than supply and when is supply price greater than demand: D(p)=-1000p+3000;S(p)=1200p-8000?

Question

when is demand price greater than supply price in interval notation and when in is supply price greater than demand?

Answer 1

I hope you know something about coordinate geometry.

 

The supply equals the demand when 1000p + 3000 = 1200p - 8000. Solving this, you get p= 55.

So for the price for [0,55), whixh means 0<=p<55, the demand curve is higher since these are linear functions andthe y intercept is higher on the Demand function.

 

The Supply function is higher for (55,infinity) or 55<p<infinity. If you can picture 2 lines intersecting, the demand curve being higher on the first interval implies that it will be lower after the point at which they are equal.

 

Hope this helped.