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Question
If the equation `4x^2-3kx+1=0` has equal roots then value of k=?
(a)`+-2/3` (b)`+-1/3`
(c)` +-3/4` (d) `+-4/3`
Solution
(d) `+-4/3`
It is given that the roots of the equation `4x^2-3kx+1=0` are equal.
∴` (b^2-4ac)=0`
⇒` (3k)^2-4xx4xx1=0`
⇒`9k^2=16`
⇒`k^2=16/9`
⇒ `k=+-4/3`
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