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The value of 'a' for which x^{2}-\left ( a-3 \right )x+a= 0 has both roots negative is 

  • Option 1)

    \left [ 0,1 \right ]

  • Option 2)

    (0,1]

  • Option 3)

    [0,1)

  • Option 4)

    \left ( 0,1 \right )

 

Answers (1)

best_answer

\left ( i \right )\: D\geq 0\: \Rightarrow\: a^{2}-6a+9-4a\geq 0

\Rightarrow \: a^{2}-10a+9\geq 0

\Rightarrow \: a\leq 1\: \cup \: a\geq 9\cdots \cdots \left ( 1 \right )

\left ( ii \right )\: \frac{a-3}{1}< 0\: \Rightarrow \: a< 3\cdots \cdots \left ( 2 \right )

\left ( iii \right )\: a> 0\cdots \cdots \left ( 3 \right )

\left ( 1 \right )\cap \left ( 2 \right )\cap \left ( 3 \right )  we get,

a\, \epsilon \, (0,1]

\therefore Option (B)

 

Both roots of a Quadratic Equation are negative -

\frac{-b}{a}< 0,\frac{c}{a}> 0

D= b^{2}-4ac\geqslant 0

- wherein

ax^{2}+bx+c=0

is the quadratic equation

 

 


Option 1)

\left [ 0,1 \right ]

This is incorrect

Option 2)

(0,1]

This is correct

Option 3)

[0,1)

This is incorrect

Option 4)

\left ( 0,1 \right )

This is incorrect

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Aadil

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