MHT CET202012 Oct 2020Evening ShiftMathematicsProperties of TrianglesActual
If A , B , C are the angles of a ABC , then with usual notations, c²-a²+b² a²-b²+c² =
Options
- AB A
- BB A
- CB A
- DB A
Correct answer
D. B A
Step-by-step solution
array l c²-a²+b² a²-b²+c² = b²+c²-a² a²+c²-b² array Dividing numerator and denominator by 2 abc . array l = ( b²+c²-a² 2 b c ) 1 a ( a²+c²-b² 2 a c ) 1 b = ( A) ( 1 a ) ( B) 1 b array = b a A B = K B K A A B ...(by Sine rule) = B A