COMEDK2017MathematicsTrigonometric Ratios & Identities
The sides a, b, c of a triangle are in AP. If = a b+c , = b c+a , = c a+b then ² 2 + ² 2 =
Options
- A1
- B1 2
- C1 3
- D2 3
Correct answer
D. 2 3
Step-by-step solution
1 = a b+c 1 = b+c a By componendo and dividendo,we have 1- 1+ = b+c-a b+c+a ² 2 = b+c-a 3 b array l a, b, c are in A.P. 2 b=a+c array 1- 1+ = a+b-c a+b-c ² 2 = a+b-c 3 b ² 2 + ² 2 = 2 b 3 b = 2 3