Question

if x=√6+√2 and y=√6-√2they xy 1)1 ,2) 2, 3)3 ,4)4​

Answer 1

✇ Given :-

• x=√6+√2
• y=√6-√2

✇ To find :-

• xy

✇ Solution :-

xy = (√6 +√2) (√6 - √2)

It is in form of the algebraic identity (a+b)(a-b)

We know that,

✇ (a + b)(a-b) = a² - b²

By applying that formula ,

xy = (√6)² - (√2)²

xy = 6 -2

xy = 4

Since, option-d is correct .

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✇Know more algebraic identities:-

➺(a+ b)² = a² + b² + 2ab

➺( a - b )² = a² + b² - 2ab

➺( a + b )² + ( a - b)² = 2a² + 2b²

➺( a + b )² - ( a - b)² = 4ab

➺( a + b + c )² = a² + b² + c² + 2ab + 2bc + 2ca

➺a² + b² = ( a + b)² - 2ab

➺(a + b )³ = a³ + b³ + 3ab ( a + b)

➺( a - b)³ = a³ - b³ - 3ab ( a - b)

➺a³ + b³ = (a+b)³ -3ab (a + b)

➺a³ - b³ = (a-b)³ +3ab (a-b)

➺If a + b + c = 0 then a³ + b³ + c³ = 3abc