JEE Main 2023 · MathsMultiple choiceSingle correctHardMulti-step

JEE Main 12 April 2023, Shift 1, Maths Q19

Question 19 of 90 in this shift, Maths question 19 of 30, Section A.

In a triangle ABC, if

\cos A+2\cos B+\cos C=2

and the lengths of the sides opposite to the angles A and C are

3

and

7

respectively, then

\cos A-\cos C

is equal to

(1) $\frac{3}{7}$
(2) $\frac{10}{7}$ Official answer
(3) $\frac{5}{7}$
(4) $\frac{9}{7}$

Official answer

Option 2

NTA final key.

Chapter: Trigonometric Functions
Topic: Properties of Triangles
Idea tested: Projection Rule

Same topic in other shifts

All Properties of Triangles questions

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29 Jul 2022, Shift 2 · Q13Let A $(\alpha,-2)$ , B $(\alpha, 6)$ and C $\left(\frac{\alpha}{4},-2\right)$ be vertices of a $\Delta$ ABC. If…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.