If 'alpha' be the angle subtended by the points `P(x_1, y_1) and Q(x_2, y_2)` at origin O, Sho...
15 views · Published 12 October 2018 · 3:33 · Indexed 25 September 2026
Channel: Doubtnut · 2018 · Education
To ask Unlimited Maths doubts download Doubtnut from - https://goo.gl/9WZjCW If 'alpha' be the angle subtended by the points `P(x_1, y_1) and Q(x_2, y_2)` at origin O, Show that `OP.OQ.cos alpha= x_1x_2 + y_1y_2`.
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