JEE Main 2020 · MathsMultiple choiceSingle correctMediumMulti-step

JEE Main 5 September 2020, Shift 1, Maths Q56

Question 56 of 75 in this shift, Maths question 6 of 25.

3^{2\sin 2\alpha-1}

, 14 and

3^{4-2\sin 2\alpha}

are the first three terms of an A.P. for some

\alpha

, then the sixth term of this A.P. is :

(1)81
(2)78
(3)66Official answer
(4)65

Official answer

Option 3

NTA final key (Sep 2020).

Chapter: Sequences and Series
Topic: AP and GP
Idea tested: Conditions for Three Terms in AP or GP

Same idea in other shifts

Asked 6× in all

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1 Feb 2024, Shift 1 · Q6Let 3, a, b, c be in A.P. and 3, a $-$ 1, b+1, c+9 be in G.P. Then, the arithmetic mean of a, b and c is :MediumSingle correct
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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.