Question

If X=4 + √15, then find the value of [x+1/x] ²

Answer 1

Answer:

64

Step-by-step explanation:

x = 4 + √15

1 /x = 1 / ( 4 + √15 )

      = 1 / ( 4 + √ 15 ) × ( 4 - √15 ) / ( 4 - √ 15 )

      = ( 4 - √ 15 ) / ( 4² - 15 )

      = ( 4 - √ 15 ) / ( 16 - 15 )

      = ( 4 - √ 15 ) / 1

      = 4 - √5

x + 1/x

= 4 + √15 + 4 - √15

= 4 + 4

= 8

( x + 1/x )² = 8²

                = 64

Answer 2

Answer:

64

Step-by-step explanation:

please refer the attachment