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1) Verify the following identities 0 = (0 + z/u ) ujs + (e - 1 ) soo (e b) sin ( x + y) + sin ( x -y) = 2 sin x cos y c) 1-cos 21 = tan x sin 2x 2) Find all solutions in the interval [0 , 2n] without the aid of a calculator. a) sin ( x + 1/6 ) - sin ( x - 1/6 ) = b) 3 tan ' x - tan x = 0 c) 2 sin 2 x + 3 sin x + 1 = 0 3) a) Use the law of cosines to find the angles in a triangle whose sides have the following lengths: a = 12 cm , b = 15 cm, c = 9 cm. b) The law of cosines can be used to establish Heron's Area Formula for the area of a triangle. Area = \\s(s - a)(s - b)(s - c) wheres = (a+b+c) 2 Use Heron's formula to find the area of the triangle in part (a)