# Math

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If
sin(x) = 1/3 and sec(y) = 29/21
, where x and y lie between 0 and π/2, evaluate the expression using trigonometric identities. (Enter an exact answer.)
cos(2y)

• Math -

cos(y) = 21/29

cos(2y) = 2cos^2(y) - 1 = 2(21/29)^2 - 1 = 41/841

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