InterviewSolution
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InterviewSolution
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Solve the equation:`x^2+3x+9=0` |
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Answer» The given equation is `x^(2)+3x+9=0`. This is of the form `ax^(2)+bx+c=0`, where a = 1, b = 3 and c = 9. `therefore" "(b^(2)-4ac)=(3^(2)-4xx1xx9)=(9-36)=27 lt 0`. So, the given equation has complex roots. These roots are given by `(-b+- sqrt(b^(2)-4ac))/(2a)=(-3 +- sqrt(-27))/(2xx1)" "[because b^(2)-4ac = -27]` `=(-3 +- isqrt(27))/(2)=(-3 +- i3 sqrt(3))/(2)` `therefore" ""solution set"={(-3+ i3 sqrt(3))/(2),(-3-i3 sqrt(3))/(2)}={(-3)/(2)+(3sqrt(3))/(2)i, (-3)/(2)-(3sqrt(3))/(2)i}`. |
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