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Find the value of k for which the quadratic equation 2x2 + kx + 2 = 0 has equal root. or |
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Answer» Given that quadratic equation 2x2 + kx + 2 = 0 has equal roots. By comparing given quadratic equation with standard quadratic equation ax2 + bx + c, we get a = 2, b = k and c = 2. We know that the quadratic equation ax2 + bx + c has equal roots, if b2 - 4ac = 0. Therefore, k2 − 4 × 2 × 2 = 0 ⇒ k2 = 16 = 42 ⇒ k = ±4. Hence, for k = ±4, the quadratic equation 2x2 + kx + 2 = 0 have equal roots. |
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