if one root of the polynomial p(y) = 5y² + 13y +m is reciprocal of other , then find the value of ‘m’ ?

answer with sol

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if one root of the polynomial p(y) = 5y² + 13y +m is reciprocal of other , then find the value of ‘m’ ?

answer with solution…

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Arya

2 thoughts on “if one root of the polynomial p(y) = 5y² + 13y +m is reciprocal of other , then find the value of ‘m’ ?<br /><br />answer with sol”

  1. EXPLANATION.

    Quadratic equation.

    ⇒ p(x) = 5y² + 13y + m.

    As we know that,

    Let one roots = α.

    Other roots is reciprocal = 1/α.

    Products of the zeroes of the quadratic equation.

    ⇒ αβ = c/a.

    ⇒ α x 1/α = m/5.

    ⇒ 1 = m/5.

    ⇒ m = 5.

    MORE INFORMATION.

    Nature of the roots of the quadratic expression.

    (1) = Real and unequal, if b² – 4ac > 0.

    (2) = Rational and different, if b² – 4ac is a perfect square.

    (3) = Real and equal, if b² – 4ac = 0.

    (4) = If D < 0 Roots are imaginary and unequal Or complex conjugate.

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  2. Given that , The one root of the polynomial p(y) = 5y² + 13y +m is reciprocal of other .

    ❍ Let’s Consider the two roots of Polynomial be [tex]\bf \alpha \:[/tex] and [tex]\bf \beta \:[/tex] .

    • The one root of the polynomial is reciprocal of other .

    [tex]\qquad\therefore \:\:\sf \beta \:=\: Reciprocal \: of \: \alpha \:\\\\[/tex]

    [tex]\qquad :\implies \sf \beta \:=\: Reciprocal \: of \: \alpha \: \:\\\\[/tex]

    [tex]\qquad :\implies \sf \beta \:=\: \dfrac{1}{\alpha } \: \:\\\\[/tex]

    [tex]\qquad \therefore \:\:\pmb{\underline{\purple{\frak{\: \beta \:(\:or \: \:other \: root \:)\:=\: \dfrac{1}{\alpha } }}} }\:\:\bigstar \\[/tex]

    ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀☆ GIVEN POLYNOMIAL : p(y) = 5y² + 13 y + m

    ⠀⠀⠀⠀As , We know that ,

    [tex]\qquad \underline { \boxed {\pmb{\red{\:\maltese \:\: Product \:of \: zeroes \:}\purple {\:\:(\:\alpha\:\beta \:)}\red{\::} }}}\\\\[/tex]

    [tex]\qquad \dashrightarrow \sf \:\:\alpha \:\: \beta \:\:=\:\:\dfrac{ \:Constant \:Term \:}{Cofficient \:of\:y^2 \:} \\\\[/tex]

    ⠀⠀⠀⠀⠀⠀[tex]\underline {\boldsymbol{\star\:Now \: By \: Substituting \: the \: known \: Values \::}}\\[/tex]

    [tex]\qquad \dashrightarrow \sf \:\:\alpha \:\: \beta \:\:=\:\:\dfrac{ \:Constant \:Term \:}{Cofficient \:of\:y^2 \:} \\\\\qquad \dashrightarrow \sf \:\:\alpha \:\: \times \:\:\dfrac{1}{\alpha \:}\:\:=\:\:\dfrac{ \:m \:}{5\:} \\\\\qquad \dashrightarrow \sf \:\:\cancel{\alpha} \:\: \times \:\:\dfrac{1}{\cancel {\alpha} \:}\:\:=\:\:\dfrac{ \:m \:}{5\:} \\\\\qquad \dashrightarrow \sf \:\:1\:\:=\:\:\dfrac{ \:m \:}{5\:} \\\\\qquad \dashrightarrow \sf \:\:1\:\times\: 5 \:=\:\: \:m \: \\\\\qquad \dashrightarrow \sf \:\:5 \:=\:\: \:m \: \\\\\qquad \dashrightarrow \sf \:\:m\:=\:\: \:5 \: \\\\\qquad \therefore \:\:\pmb{\underline{\purple{\frak{\: \:\:m\:=\:\: \:5 \: }}} }\:\:\bigstar \\[/tex]

    [tex]\qquad \therefore \:\underline {\sf \:Hence,\:The \:value \:of \: m \: is \:\bf \:5 \:}\\[/tex]

    ⠀⠀⠀⠀⠀━━━━━━━━━━━━━━━━━━━⠀

    ⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀☆ More To Know :

    [tex]\qquad \qquad \boxed {\begin{array}{cc} \bf{\underline {\bigstar\:\: For \: a \:Quadratic \:Polynomial \::}}\\\\ \sf{ Whose \:\:zeroes \:\:are\:\:\alpha \:\&\;\: \beta\:\:} \\\\ 1)\:\: \alpha + \beta \: =\:\dfrac{-b}{a} \quad \bigg\lgroup \bf Sum\:of\;Zeroes \bigg\rgroup \\\\ 2)\:\: \alpha \times \beta \: =\:\dfrac{c}{a} \quad \bigg\lgroup \bf Product \:of\;Zeroes \bigg\rgroup \\\\ \end{array}} [/tex]

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