Math, asked by sambhavjain507, 9 months ago

If alpha beta are roots of equation X square - 2 X + 2 equal to zero then Alpha square plus beta square is

Answers

Answered by kaushik05
87

Given:

 \bold{ \alpha  \: and \:   \beta  \: are \: the \: roots \: of \: equation}

 \star \bold{f(x) = {x}^{2}  - 2x + 2 = 0}

To Find :

 \star \bold{  { \alpha }^{2}  +  { \beta }^{2} }

Here :

a = 1 , b=-2 and c= 2

As we know that :

 \star \:  \alpha  +  \beta  =  \frac{ - b}{a}  =  \frac{ - ( - 2)}{1}  = 2 \\  \\  \star \:  \alpha  \beta  =  \frac{c}{a}  =  \frac{2}{1}  = 2

Now :

 \implies \:  { \alpha }^{2}  +  {  \beta }^{2}  = ( { \alpha  +  \beta )}^{2}  - 2 \alpha  \beta  \\  \\  \implies \:  { \alpha }^{2}  +  { \beta }^{2}  = ( {2)}^{2}  - 2(2) \\  \\  \implies \:  { \alpha }^{2}  +  { \beta }^{2}  = 4 - 4 \\  \\  \implies \:  { \alpha }^{2}  +  { \beta }^{2}  = 0

Hence ,The value is 0

Answered by rajsingh24
93

QUESTION :-

=> If alpha beta are roots of equation X square - 2 X + 2 equal to zero then Alpha square plus beta square is.

SOLUTION :-

=> Let, α and β be roots of equation.

=> f(x) = x²-2x + 2 = 0

=> On comparing with ax²+bx+c then we get,

=> • a = 1 • b = -2. • c = 2

=> .°. Sum of zeroes = α + β

=> -b/a = -(-2)/1 = 2.

=> .°. Product of zeroes = αβ

=> c/a = 2/1 = 2.

Now,

=> We have to find out, α² + β²,

=> .°. α² + β² = (α + β)² - 2αβ

=> α²+β² = (2)²-2(2)

=> α²+β² = 4 - 4

=> .°. α²+β² = 0

Therefore, the value of α²+β² is 0.

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