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PROVE THAT ; Q)TAN 1*TAN 2*TAN3*......*TAN89 = 1 |
| tan1 * tan2 * tan3 * -------tan89 = tan1 * tan2 * tan3 *----tan44 * tan45 * cot44 * cot43 cot42 * cot41 * -------cot1 = tan45 * 1(tanA = 1/ cotA) = 1 (since tan45 = 1) |
