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Saturday, 31 October

JEE Main 2021 · MathsNumerical answerNumerical valueMediumCalculation

JEE Main 3 August 2021, Shift 2, Maths Q90

Question 90 of 90 in this shift, Maths question 30 of 30, Section B.

Let a⃗=2i^+αj^+k^\vec{a} = 2\hat{i} + \alpha\hat{j} + \hat{k} and b⃗=βi^−5j^+γk^\vec{b} = \beta\hat{i} - 5\hat{j} + \gamma\hat{k}, where α\alpha, β\beta and γ\gamma are real numbers. If a⃗×b⃗=26i^−11j^−19k^\vec{a}\times\vec{b} = 26\hat{i} - 11\hat{j} - 19\hat{k}, then α−β+γ\alpha - \beta + \gamma is equal to ‾\underline{\hspace{2em}}.

Official answer

7

NTA final key.

Same idea in other shifts

Asked 2× in all
  1. 10 Apr 2023, Shift 1 · Q16Let O be the origin and the position vector of the point P be −i^−2j^+3k^-\hat{i}-2\hat{j}+3\hat{k}. If the position vectors of the points A, B and…MediumSingle correct

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.