00:01
Okay, so we're asked to determine the truth values for a statement there exists some x for all y such that x is less than equal y squared.
00:09
If the domain for the variables consists of a positive real numbers.
00:22
Well, is this true if x or if a is positive your own number? well, let's say that there does exist some number x such that the statement is true.
00:48
So we have that x is equal to y squared or actually that's that y is equal to the square root of x over 2 since y is said to be positive since x is positive then if we squared us we get y squared it's equal to x over 4 so that's less than x so the square is less than x and that's x can't be x is not the value for which is the same in the 2 so that's less than x so that's, x can't be x is not the value for which the same in the two.
01:30
This is a contradiction and we can see that there does not exist a value x such that the statement is true.
01:39
For part b, we have integers.
01:46
There exists some x that for all y, x is less than equal to y squared.
01:52
Well, let's see, well, if y is an integer, then every value or every integer squared is still an integer, so we can find some value x such that this is true.
02:10
So this is also true...