A) \[1\]
B) \[2\]
C) \[3\]
D) \[4\]
Correct Answer: B
Solution :
Given equation is \[{{x}^{2}}-2x(1+3k)+7(2k+3)=0.\] For equal roots, discriminant \[=0\] \[\therefore \] \[4{{(1+3k)}^{2}}=4\times 7(2k+3)\] \[\Rightarrow \] \[1+9{{k}^{2}}+6k=14k+21\] \[\Rightarrow \] \[9{{k}^{2}}-8k-20=0\] \[\Rightarrow \] \[(9k+10)\,(k-2)=0\] \[\Rightarrow \] \[k=2,\,\frac{-10}{9}\]You need to login to perform this action.
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