Find the set of values of k for which the equation 2x(sqrd) + kx + 2 = 0 has no real roots. i have no idea how to solve this... can somone please explain? thanks
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Originally Posted by RubbishAtMaths Find the set of values of k for which the equation 2x(sqrd) + kx + 2 = 0 has no real roots. i have no idea how to solve this... can somone please explain? thanks A quadratic equation of the form $\displaystyle ax^2+bc+c = 0 $ has no real roots when its discriminant ($\displaystyle b^2-4ac$) is less than 0. In other word, you have to find values of k for which: $\displaystyle k^2-4(2)(2) < 0$
Originally Posted by Mush A quadratic equation of the form $\displaystyle ax^2+bc+c = 0 $ has no real roots when its discriminant ($\displaystyle b^2-4ac$) is less than 0. In other word, you have to find values of k for which: $\displaystyle k^2-4(2)(2) < 0$ $\displaystyle k^2 < 16$ so is the answer $\displaystyle -4 < k < 4$?
Originally Posted by RubbishAtMaths $\displaystyle k^2 < 16$ so is the answer $\displaystyle -4 < k < 4$? Yep!
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