Math

prove: tan10+tan70+tan100=tan10.tan70.tan100

asked by Rabinprakash Dahal
  1. Haven't tried it, but look at this:

    https://answers.yahoo.com/question/index?qid=20150724191938AAydOpZ

    sure looks messy, I am sure there is an easier way

    posted by Reiny
  2. 100+70 = -10
    Adding 'tan' on both sides,
    tan(100+70)= -tan10
    (tan100+tan70)/1-tan100.tan70 = -tan10
    Multiplying 1-tan100.tan70 with -tan10,
    tan100+ tan70= -tan10+tan10.tan100.tan70
    tan10+tan100+tan70= tan10.tan70.tan100 proved

    posted by Saloni

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