Arithmetic Sequences & Series (Q22 IGCSE P1 Edexcel January 2023)

Описание: In this video, Lee Guffick, founder of Guffick Tuition and former Head of Mathematics, works through Question 22 from the January 2023 Edexcel IGCSE Paper 1 — a classic Grade 9-level arithmetic sequences and series problem.

Lee explains clearly how to:
✅ Use the nth-term formula
𝑢
𝑛
=
𝑎
+
(
𝑛
−
1
)
𝑑
u
n
​

=a+(n−1)d to form an expression for n in terms of t
✅ Substitute into the sum of an arithmetic series formula
𝑆
𝑛
=
𝑛
2
(
2
𝑎
+
(
𝑛
−
1
)
𝑑
)
S
n
​

=
2
n
​

(2a+(n−1)d)
✅ Simplify step-by-step to express
𝑆
𝑛
S
n
​

in the required form
𝑝
(
𝑞
𝑡
–
1
)
𝑟
p(qt–1)
r

✅ Identify the integer values of p = 2, q = 4, r = 2

Perfect for students aiming for a Grade 8 or 9 in IGCSE Maths, this video demonstrates how algebraic reasoning and formula manipulation combine to secure every mark in longer sequence questions.

⏱️ TIMESTAMPS:
00:00 – Introduction
00:25 – Identifying the given information
00:50 – Using the nth-term formula
01:40 – Finding n in terms of t
02:20 – Substituting into the sum formula
03:10 – Simplifying and collecting like terms
03:50 – Factoring and expressing in the required form
04:30 – Final answer (p = 2, q = 4, r = 2) and key takeaways

✏️ TOPICS COVERED:

Arithmetic sequences and series

nth-term formula

Sum of an arithmetic progression

Algebraic manipulation

Expressing results in required forms

💯 EXAM TIPS:

Always start by writing both standard formulas clearly before substitution.

Be methodical when expanding brackets — sequence questions reward clear structure.

Check your algebra by substituting simple values for t to verify.

Look for ways to factor expressions into the required format — often the hardest step.

📚 ABOUT GUFFICK TUITION:
Lee Guffick is a former Head of Mathematics and A-Level Examiner who helps ambitious students achieve Grade 9/A* results and secure offers from Oxford, Cambridge, Imperial and Ivy League universities. His lessons focus on clarity, reasoning and exam confidence.

📅 JOIN OUR PROGRAMMES:
→ 1:1 Tutoring: https://www.gufficktuition.com/tutoring

→ Small-Group Classes: https://www.gufficktuition.com/group-...

→ Summer Intensive Courses: https://www.gufficktuition.com/tutoring

📱 CONNECT WITH US:
→ Instagram: @leeguffick

→ Website: https://www.gufficktuition.com

→ Email: [email protected]

#IGCSE #IGCSEMaths #EdexcelMaths #ArithmeticSequences #ArithmeticSeries #SequencesAndSeries #Grade9Maths #MathsTutor #OnlineMathsTutor #GuffickTuition #LeeGuffick