JEE Main 2026 — Vector Algebra Question with Solution
JEE Main 2026 (02 April Shift 2)
Question
Two adjacent sides of a parallelogram PQRS are given by and . If the side PS is rotated about the point P by an acute angle in the plane of the parallelogram so that it becomes perpendicular to the side PQ, then is equal to:
Choose an option
Show full solutionCorrect option: B
Correct answer
B
Step-by-step explanation
Let be the angle between the vectors and .
The side PS is rotated by an acute angle in the plane of the parallelogram to become perpendicular to PQ. The new angle between the sides is .
The given expression is .
Using the trigonometric identity :
Substituting :
Answer:
The side PS is rotated by an acute angle in the plane of the parallelogram to become perpendicular to PQ. The new angle between the sides is .
The given expression is .
Using the trigonometric identity :
Substituting :
Answer:
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This is a previous-year question from JEE Main 2026, covering the Vector Algebra chapter of Mathematics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.