Question 810241
Find the soultion for sin^2x + 3sin - 1 = 0 in radian
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sin^2x + 3sinx - 1 = 0
solve for sinx by quadratic formula:
{{{sinx = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
a=1, b=3, c=-1
ans:
sinx=3.3028(reject,(-1 < sinx < 1)
or
sinx&#8776;-0.3028
x&#8776;3.4492, 5.9556 (in quadrants III and IV where sin<0)