Question

If x = 2 +√3, find x2-1​

Answer 1

x = 2 + √3

To find :- x² - 1

( 2 + √3 ) ² - 1

Using the identity

( a + b ) ² = a² + 2ab + b²

2² + 2 x 2 x √3 + √3² - 1

4 + 4√3 + 3 - 1

4√3 + 7 - 1

4√3 + 6

2 ( 2√3 + 3 ) ➡ Answer