Math, asked by kamleshkaur3021, 4 months ago

if the real root exists of the following quadratic equation 2x^2-5x-3=0 then find the roots of the equations

Answers

Answered by Adithyapanjiyara
0

Answer:

To find -Root and Discriminant

Step-by-step explanation:

a=2,b=-5,c=-3

D=b^2-4ac

=>(-5)^2-4*2*(-3)

=>25+24

=>49

This equation will have roots because D>0

x=-b/2a+-√49/2a

=>5/4+-7/4

=>5/4+7/4 or 5/4-7/4

=>12/4 or -2/4

=>x=3,-1/2

Hope this will help you

Please make my answer the braniest

Answered by SuitableBoy
127

{\huge{\underline{\underline{\rm{Question:-}}}}}

Q) If the real roots exists of the following Quadratic Equation 2x² - 5x - 3 = 0 Then find the roots of the Equation .

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{\huge{\underline{\underline{\rm{Answer\checkmark}}}}}

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\bf{Given}\begin{cases}\sf{Equation→}\bf{2x^2-5x-3=0} \\ \rm{The \; Equation\; has \; real \; roots } \end{cases}

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To Find :

  • The roots of the Equation .

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Solution :

We can Solve it using two methods :

{\underline{\textit{\textbf{1st\;Middle\;Term\;Splitting}}}}

 \mapsto \rm \: 2 {x}^{2}  - 5x - 3 = 0

 \mapsto \rm \: 2 {x}^{2}   -  6x + x - 3 = 0

 \mapsto \rm \: 2x(x - 3) + 1(x - 3) = 0

 \mapsto \rm \: (2x + 1)(x - 3) = 0

Either :

 \rightarrow \rm \: 2x  + 1 = 0

 \rightarrow \rm \: 2x =  - 1

  \rightarrow \: {\underline{ \boxed{ \pink{ \rm{ x =  \frac{ - 1}{2} }}}}}

Or :

 \rightarrow \rm \: x - 3 = 0

 \rightarrow \underline{ \boxed{ \pink{ \rm{x = 3}}}}

So ,

# Roots : \bold{\dfrac{-1}{2}} and 3 .

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_________________________

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{\underline{\textit{\textbf{2nd\; Quadratic\;Formula}}}}

In this equation ,

 \boxed{ \sf{2 {x}^{2}  - 5x - 3 = 0}}

Compare it with standard equation

 \boxed{ \sf{a {x}^{2}  + bx + c = 0}}

So ,

  • a = 2
  • b = -5
  • c = -3

Using the Quadratic Formula :

 \boxed{ \sf{roots =  \frac{ - b \pm \:  \sqrt{ {b}^{2}  - 4ac} }{2a}}}

 \mapsto \rm \: roots =  \frac{ - ( - 5) \pm \:  \sqrt{ {( - 5)}^{2}  - 4(2)( - 3)} }{2 \times 2}  \\

 \mapsto \rm \: roots =  \frac{5 \pm \:  \sqrt{25 + 24} }{4}  \\

 \mapsto \rm \: roots =  \frac{5 \pm \:  \sqrt{49} }{4}  \\

 \mapsto \rm \: roots =  \frac{5 \pm7}{4}  \\

So ,

 \rightarrow \rm \: first \: root =  \frac{5 + 7}{4}  \\

 \rightarrow \rm \: first \: root =  \frac{ \cancel{12}}{ \cancel4}  \\

 \rightarrow \underline{ \boxed{ \pink{ \rm {first \: root = 3}}}}

And ,

 \rightarrow \rm \: second \:root=  \frac{5 - 7}{2}  \\

 \rightarrow \rm \: second \:root=  \frac{ -  \cancel2}{ \cancel4}  \\

 \rightarrow \underline{  \boxed{ \pink{ \rm{second \: root =  \frac{ - 1}{2} }}}}

So ,

# Roots : \bold{\dfrac{-1}{2}} and 3 .

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So , By both methods , we get same answer .

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