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Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
Sequences & Series
Watch comprehensive video reviews for Sequences & Series, designed for final exam preparation. Each video includes integrated problems you can solve alongside detailed solutions.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
Not your average video:
Interactive Problems: Solve problems alongside the video with step-by-step guidance and detailed solutions.
Exam Preparation: Complete unit reviews designed for final exam preparation with all key concepts covered systematically.
Expert Teaching: High-quality instruction from Perplex co-founder James Mullen with clear explanations, worked examples, and exam tips.
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SL Core 1.3
The nth term of a geometric sequence is given by
where u1 is the first term and r is the common ratio.
Example
A geometric sequence has u2=9 and u5=31. Find the first term and the common ratio.
Using the formula, we have
Dividing u5 by u2:
so
Now since u2=u1r=9, u1=r9=9⋅3=27.
SL Core 1.3
The nth term of a geometric sequence is given by
where u1 is the first term and r is the common ratio.
Example
A geometric sequence has u2=9 and u5=31. Find the first term and the common ratio.
Using the formula, we have
Dividing u5 by u2:
so
Now since u2=u1r=9, u1=r9=9⋅3=27.