00:01
Okay, so the elasticity of demand can be calculated as follows.
00:07
So, e of p, the function here, is going to be equal to, well, the elasticity of demand, is, well, typically it's q equals f of p, and it's equal to negative p times f prime of p.
00:33
Divided by f of p.
00:39
Okay, where here p is our given price and the elasticity of demand is denoted by e of p.
00:49
So for part a, we're given that the quantity of, let's see, cellular phone to be sold at p dollars is given as q is equal to 10 ,000 divided by p plus 50, and then minus 30.
01:13
So here we let q be equal to f of p, and then we have f of p is then equal to 10 ,000 over p plus 50 minus 30.
01:25
Okay, so therefore the derivative f prime of p, well, is going to be equal to negative 10 ,000, divided by the quantity, p plus 50 square okay so then we just take f prime of p and divided by f of p okay so um what we end up with is negative 10 ,000 over p plus 50 um divided by uh 10 ,000 uh 10 ,000 minus 30 times the quantity p plus 50, which gives us negative 10 ,000 over p plus 50 times the quantity 8 ,500 minus 30 p.
02:43
Okay.
02:48
Okay.
02:48
So now negative p times f prime of p over f of p is again equal to negative 10 ,000 times p plus 50 times 8500 minus 30p...