Question

If sinx = 1/3 and sec y = 5/4, where x and y lie btwn 0 and pi/2, evaluate sin(x+y).

Answer 1

sin (A + B) = sin A cos B + cos A sin B

If sec y = 5/4, then cos y = 4/5.

sin (x + y) = sin x cos y + cos x sin y

sin (x + y) = (1/3)(4/5) + (2√2/3)(3/5)

sin (x + y) = 4/15 + 2√2/5

4 + 6√2
------------ = sin(x + y) <==ANSWER
. 15

Answer 2

how did u get 2sqtr 2 / 3 as cos x?. for some reason i got sqrt 8/3.

Answer 3

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