MATHEMATICS · Single correct · A Level · Mathematics · Trigonometry · Trigonometry
Problem
ABC is a triangle such that sin(2A+B)=sin(C−A)=−sin(B+2C)=21. If A, B, and C are in AP, then the values of A, B, and C are
(1) 45∘,60∘,75∘
(2) 30∘,60∘,90∘
(3) 20∘,60∘,100∘
(4) None of these