A value of $k$ for which the quadratic equation ${x^2} - 2x\left( {{\rm{l}} + 3k} \right) + 7\left( {2k + 3} \right) = 0$ has equal roots, is

JEE MATHEMATICS MCQ: QUADRATIC EQUATIONS

1 Easy

1 of 1

Application +4 | -1

A value of

k

for which the quadratic equation

{x^2} - 2x\left( {\mathrm{l} + 3k} \right) + 7\left( {2k + 3} \right) = 0

has equal roots, is

View answer and explanation

Correct option: B

Option B (2) is correct because when k=2, the discriminant of the quadratic equation is zero, indicating equal roots.

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\log _7 \log _5(\sqrt{x+5}+\sqrt{x})=0

\alpha ,\beta

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\alpha < 1 < \beta ,

\alpha ,\;\beta

{x^2} - px + q = 0

{\alpha _1},{\beta _1}

{x^2} - qx + p = 0,

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{x^2} + 4ax + 2 > 0

x

a

f\left( x \right) = a{x^2} + bx + c\;

\;f\left( { - 1} \right) < 1,f\left( 1 \right) > - 1,f\left( 3 \right) < - 4\;

\;a \ne 0,

9{x^2} - 18\left| x \right| + 5 = 0

f\left( x \right) = \log \left( {{x^2} - x - 2} \right)