 Hello and welcome to the session. In this session, we will discuss the following question and the question says, tell which of the following relations are functions, part a is y is equal to 2x plus 3, part b is x is equal to y squared plus 4. In part c, we are given two sets in which the element 12 from the first set is mapped to number of planets and number of bananas in one dozen and 31 is mapped to number of days in January. Let's start the solution now. In part a, we are given y is equal to 2x plus 3. We have to find whether this relation is a function or not. We know that a relation is a function if each element of domain has a unique image. Also for this relation, we can see that for each value of x there exists a unique value of y. So, we can say that since each value of x gives only one value of y, therefore y is equal to 2x plus 3 is a function. So, this is our answer for part a. Now in part b, we are given x is equal to y squared plus 4. Now if we take y is equal to 1, then x is equal to 1 squared plus 4 which is equal to 5. Now let y is equal to minus 1, then x is equal to minus 1 squared plus 4 which is again equal to 5. So, for two different values of y, we get the same value of x. So, the ordered pair 5, 1 and the ordered pair 5 minus 1 have same first component and we know that the condition for a relation to be a function is that no two ordered pairs in the relation should have same first component. Therefore, we can say that x is equal to y squared plus 4 is not a function. Now we will move on to part c. Here the first box represents the domain and the second box represents the range. We can see that the element 12 is mapped to two different elements in the range. Hence the element 12 has more than one images. So, we can say that since the element 12 has more than one image, therefore the given relation is not a function. This completes part c and with this we end our session. Hope you enjoyed the session.