Union and intersection of intervals

Question

Struggling with Union and intersection problems

C and D are sets of real numbers defined as follows



C={x|x≤3}

D={x|x>8}

Write C∪D and C∩D using interval notation.

If the set is empty, write Ø

Answer 1

CUD = (-infinity, 3]U(8, infinity)

C intersection D = the null set