a) To write the figure number and the corresponding number of dots:
b) To identify the type of relation between the figure number and the number of dots in a figure:
For the first figure,
1+3+1=5
For the second figure,
For the third figure,
For the fourth figure,
c) To tell whether this relation is a function or not:
Yes, it is a function.
d) To explain part (c) and find the algebraic expression:
For every n ( figure number) value, there is a unique D (number of dots) value.
So, this relation represents the function.
Then, the algebraic expression is,