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# Trigonometric Graphs

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[size=150]Hi well I am doing my maths homework and the question was "Solve these equations, correct to 0.1 for 0<x<360 5(a) 4sinx+1=0 and then i got a fraction which was -1/4", now my teacher always says "solve for the positive" but could I turn the top half of this fraction be turned into a positive? [/size]
Guest Feb 2, 2012
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#1
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sin x = - 1/4, x=(-1)^n arcsin (-1\4) + \pi n = (-1)^{n+1} arcsin 1/4

(asin(-0.25))

subtract from 360 an absolute value of this angle and you get a positive number (I guess you're aware that "- angle" means way clockwise from the 0 grades point on the 360 grades circle) that is identical to the found root of the equation.
scrutinizer  Aug 26, 2013

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