Find cos (x + y) if sin x = 5/13 and sin y = 4/6

Question

Mathematics

Ricky Bates

21 November, 19:14

Find cos (x + y) if sin x = 5/13 and sin y = 4/6

+2

Answers (1)

Know the Answer?

Gregory Peck · Answer 1

According to the trigonometric identities, cos (x + y) = cos x cos y - sin x sin y. cos x = sin y and cos y = sin x via the complementary theorem. given the data, sin x = 5/13 and sin y = 4/6, then via substitution,

cos (x+y) = 4/6 * 5/13 - 5/13 * 4/6 = 0.

The answer hence is zero.