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प्रश्न
Find the value of k for which the quadratic equation `9x^2-3kx+k=0` has equal roots.
उत्तर
It is given that the quadratic equation `9x^2-3kx+k=0` has equal roots.
∴ `D=0`
⇒`(-3k)^2-4xx9xxk=0`
⇒`9k^2-36k=0`
⇒`9k(k-4)=0`
⇒`k=0 or k-4=0`
⇒`k=0 or k=4`
Hence, 0 and 4 are the required values of k.
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