Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Mathematics
Mathematics
Problem
For
u
n
=
3
n
−
1
u_n = 3n - 1
u
n
=
3
n
−
1
, write
u
1
+
u
2
+
u
3
+
⋯
+
u
20
u_1 + u_2 + u_3 + \dots + u_{20}
u
1
+
u
2
+
u
3
+
⋯
+
u
20
using sigma notation and evaluate the sum.
Browse the problem library