00:01
Let's take a look at this problem.
00:03
So, consumer preferences over two goods x1 and x2 is given by a utility function u x1, x2 which is equal to x1 power 1 by 2 plus x2 power 1 by 2.
00:23
So, now i want to check for the monotonicity and the convexity for these preferences.
00:41
Okay, so let's briefly discuss the monotonicity first.
00:59
Okay, so monotonicity means that more of a good is always preferred to less of a good.
01:25
Now, we have the utility function as x1 1 by 2 plus x2 power 1 by 2.
01:33
Now, from this we can see that the consumer always prefer a bundle with more of both goods more of both goods to a bundle with less of both goods.
02:11
Okay, so let's look at our convexity.
02:25
The convexity refers to the property that if a consumer prefers one bundle of goods over another he will always prefer any bundle that is a weighted average of those two bundles.
02:39
So, if a consumer prefers one bundle of good over another then he always prefers any bundle, any good that is the weighted average of those two bundles.
03:33
Okay, so let's take our utility function here u x1 comma x2 is given by x1 power 1 by 2 plus x2 power 1 by 2.
03:47
So, let's check for the monotonicity.
03:50
Let's find my marginal utility.
04:01
Now, for good x1 the marginal utility mu x1 is equal to the partial derivative with respect to x1 dou u by dou x1 which is equal to 1 by 2 x1 power minus 1 by 2...