1) eix 2) e-ix 3) ex 4) e-x Solution: (4) e-x cos ix + i sin ix = cos hx + i i sin hx = cos hx - sin hx = [ex + e-x - ex + e-x] / 2 = e-x... View Article
1) cos x cos hy 2) sin x sin hy 3) - sin x sin hy 4) cos x sin hy Solution: (1) cos x cos hy cos (x + iy) = A + iB cos x cos (iy) - sin x... View Article
1) a 2) b 3) [a + b] / [1 - ab] 4) [a - b] / [1 + ab] Solution: (4) [a - b] / [1 + ab] Put a = tan θ, b = tan ɸ and x = tan ψ, then reduced... View Article
1) √(x3/8) 2) x2/2 3) πx2 4) 3x2/2 Solution: Let ABC be the triangle such that AB = AC = x And let ∠ACB = sin θ Draw AD perpendicular to BC.... View Article
1) 1 2) 2 3) 4 4) None of these Solution: Consider the figure below. From ∆ADC, sin (y + z)/DC = sin C/AD .....(1) From ∆ABD sin x/BD =... View Article
1) a, c, and b are in AP 2) a, b, and c are in GP 3) b, a, and c are in AP 4) a, b, and c are in AP Solution: Given tan A/2 = 5/6, tan C/2 =... View Article
(1) 0 (2) abc (3) a + b + c (4) 1 Solution: (b + c) cos A + (a + c) cos B + (a + b) cos C = b cos A + c cos A + a cos B + c cos B + a cos C... View Article
1) GP 2) AP 3) HP 4) None of these Solution: Given cot A, cot B, and cot C are in AP. So cot B - cot A = cot C - cot B cos B/sin B - cos... View Article
1) 1/3 2) 1/9 3) 1/27 4) 1/18 Solution: Let 4 sin A = 4 sin B = 3 sin C = k sin A = k/4, sin B = k/4, sin C = k/3 From sine rule, we have... View Article