Polynomial of degree seven can have the maximum 7 real solutions,
so maximum number of x-intercepts is also 7.
I believe it the second one :)
Given:
The sets are
and
.
To find:
Whether A and B are disjoint sets or not.
Solution:
Two sets are called disjoint sets if there are no common elements between them.
We have,


Clearly, there is not common elements between the set A and set B.
Therefore, the sets A and B are disjoint sets.