Mastering arithmetic and geometric sequences can be tough for students. Many face some common challenges:

• Understanding formulas: It can be hard to remember or use formulas. For example, the formula for the nth term of arithmetic sequences is $a_n = a_1 + (n - 1)d$. For geometric sequences, it’s $a_n = a_1 r^{n-1}$.

• Identifying patterns: Spotting patterns in sequences can be tricky, and this can lead to mistakes.

To tackle these challenges, it's important to practice different kinds of problems regularly.

Also, asking teachers or classmates for help can really strengthen understanding and boost confidence.