Published by:
CGP EDU Academic Team
Published on: August 12, 2026
If 4 cos A cos B + sin 2A + sin 2B + sin 2C = 4 then Δ ABC is
Text Solution
Verified by ExpertsThe correct answer is:
C
4 cos A cos B + 4 sin A sin B sin C = 4
sin C = 
≤ 1 ... (1)
⇒ cos (A – B) ≥ 1
⇒ cos (A – B) = 1
True if A = B … (2)
Put (2) in (1)
sin C = 1
C = 90 0
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
In a Δ ABC, if P,Q,R divide sides AB, BC, CA respectively in k : 1. If , then k equals
In a triangle ABC, cos A cos B + sin A sin B sin C = 1, then the triangle is -
In a triangle ABC, =
If P is a point on the altitude AD of the triangle ABC such that ∠ PBD = , then AP is equal to -
In a Δ ABC, if a, b, c and A are given, then there are two Δ ’s with third sides c 1 and c 2 , then…
In a triangle ABC, tan = , tan = , then –