Question
Question: In a \(\triangle A B C\) \(2 a c \sin \left( \frac { A - B + C } { 2 } \right)\) is equal to...
In a △ABC 2acsin(2A−B+C) is equal to
A
a2+b2−c2
B
c2+a2−b2
C
b2−c2−a2
D
c2−a2−b2
Answer
c2+a2−b2
Explanation
Solution
2acsin2A−B+C=2acsin2π−2B=2accosB
=2ac2cac2+a2−b2=c2+a2−b2.