74 tan 44 tan 34 = tan 74 — tan 44 — tan 34,

1.	74 tan 44 tan 34 = tan 74 — tan 44 — tan 34,
Answer» To prove:tan 7a tan4a tan 3a=tan 7a -yan 4a-tan 3aFormula used tan(7a) = tan(3a + 4a) RHS:tan(7a) - tan(4a) - tan(3a) => tan(3a + 4a) - tan(4a) - tan(3a) => (tan(3a) + tan(4a)) / (1 - tan(3a) * tan(4a)) - tan(4a) - tan(3a) => (tan(3a) + tan(4a)) / (1 - tan(3a) * tan(4a)) - (tan(3a) + tan(4a)) => (tan(3a) + tan(4a)) * (1 / (1 - tan(3a) * tan(4a)) - 1) => (tan(3a) + tan(4a)) * (1 - 1 + tan(3a) * tan(4a)) / (1 - tan(3a) * tan(4a)) => (tan(3a) + tan(4a)) * tan(3a) * tan(4a) / (1 - tan(3a) * tan(4a)) =>tan(3a + 4a) * tan(3a) * tan(4a) => tan(7a) * tan(3a) * tan(4a)=LHSHence provedLike if you find it useful

Answer»

To prove:tan 7a tan4a tan 3a=tan 7a -yan 4a-tan 3aFormula used

tan(7a) = tan(3a + 4a)

RHS:tan(7a) - tan(4a) - tan(3a) =>

tan(3a + 4a) - tan(4a) - tan(3a) =>

(tan(3a) + tan(4a)) / (1 - tan(3a) * tan(4a)) - tan(4a) - tan(3a) =>

(tan(3a) + tan(4a)) / (1 - tan(3a) * tan(4a)) - (tan(3a) + tan(4a)) =>

(tan(3a) + tan(4a)) * (1 / (1 - tan(3a) * tan(4a)) - 1) =>

(tan(3a) + tan(4a)) * (1 - 1 + tan(3a) * tan(4a)) / (1 - tan(3a) * tan(4a)) =>

(tan(3a) + tan(4a)) * tan(3a) * tan(4a) / (1 - tan(3a) * tan(4a)) =>tan(3a + 4a) * tan(3a) * tan(4a) =>

tan(7a) * tan(3a) * tan(4a)=LHSHence provedLike if you find it useful

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