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Solve `2cos^2x+3sinx=0`. |
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Answer» `2(1-sin^2x) + 3sinx = 0` `-2sin^2x + 3sinx + 2=0` `2sin^2x - 3sinx - 2=0` let `sinx = t` `2t^2 - 3t -2 = 0` `(2t +1)(t-2) = 0` `t = -1/2 or t=2` `sin x = -1/2 or sinx = 2` solution is not possible for `sinx = 2` `:. sinx = - sin(pi/6) = sin(-pi/6)` `x = npi + (-1)^n(-pi/6) ; n in z` answer |
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