AP EAMCET202124 Aug 2021Morning ShiftMathematicsTrigonometric Ratios & IdentitiesActual
In a A B C, 2 a c 1 2 (A-B+C) is equal to
Options
- Aa^2+b^2+c^2
- Ba^2+b^2-c^2
- Ca^2+c^2-b^2
- Db^2+c^2-a^2
Correct answer
C. a^2+c^2-b^2
Step-by-step solution
aligned & In a A B C & A+B+C=180^ & Then, 2 a c 1 2 (A-B+C) & 2 a c 1 2 (180-B-B) [ A+C=180^ -B ] & 2 a c (90^ -B ) & =2 a c B [ (90- )= ] & =2 a c a^2+c^2-b^2 2 a c [ B= a^2+c^2-b^2 2 a c ] & =a^2+c^2-b^2 aligned