JEE Mains · Maths · STD 11 - 8. sequence and series
Let the first term \(a\) and the common ratio \(r\) of a geometric progression be positive integers. If the sum of its squares of first three terms is \(33033\), then the sum of these three terms is equal to
- A \(231\)
- B \(210\)
- C \(220\)
- D \(241\)
Answer & Solution
Correct Answer
(A) \(231\)
Step-by-step Solution
Detailed explanation
\(\Rightarrow a^2+a^2 r ^2+a^2 r ^4=33033\) \(\Rightarrow a^2\left( r ^4+ r ^2+1\right)=3 \times 7 \times 11^2 \times 13 \Rightarrow a=11\) \(\Rightarrow r ^4+r^2+1=273 \quad \Rightarrow r^4+r^2-272=0\)…
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