AP EAMCET201823 Apr 2018Morning ShiftMathematicsProperties of TrianglesActual
In A B C , a^3 (B-C)+b^3 (C-A)+c^3 (A-B)=
Options
- Aa b c
- Ba + b + c
- C2 abc
- D3 abc
Correct answer
D. 3 abc
Step-by-step solution
In aligned & A B C, a^3 (B-C) & =a^3 ( 2 (B+C) (B-C) 2 (B+C) ) & =a^3 ( 2 B+ 2 C) 2 (B+C) ) & =a^3 ( 2 B B+2 c C 2 ( -A) ) & =a^3 ( B B+ C C A ) & =a^3 ( b k B+c K C a k ) aligned Adding Eqs. (i), (ii) and (iii), we get aligned & a^3 (B-C)+b^3 (C-A)+c^3 (A-B) & =a^2 b B+a^2 c C+b^2 c C & +b^2 a A+c^2 a A+c^2 b B & =a b(a B+b A)+a c(a C+c A) & =a b c+a b c+a b c=3 a b c +b c(b C+c B) aligned