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If A+B+C =πProve that..tan2A + tan2B + tan2C = tan2A tan2B tan2C |
| Answer» We have, A + B + C = π Or, 2A + 2B + 2C = 2πOr, 2A + 2B = 2π -- 2COr, tan(2A+2B) = tan(2π -- 2C)Or,{(tan2A+tan2B)/ (1-tan2A tan2B)}= -tan2COr,tan2A+tan2B = -tan2C + tan2A tan2B tan2COr,tan2A+tan2B+tan2C = tan2A tan2B tan2C | |