Question

x = (4 - root15), find the value of ( x + 1/x)

Answer 1

x= (4-root15)
then( x+1/x)=(4-root15+1/(4-root15))
=(4-root15)2+1/(4-root15)
=((4)2+(root15)2-2×4×root15+1)/(4-root15)
=(16+15-8root15+1)/(4-root15)
=(16+16-8root15)/(4-root15)
=(32-8root15)/(4-root15)
=8 (4-root15)/(4-root15)
x+1/x=8

Answer 2

Answer:

8

Step-by-step explanation:

1 1

----- = -------------

x 4 - √15

1 4 + √15

= ------------- × ----------------

4 - √15 4 + √15

4 + √15

= --------------------------

(4 - √15) (4 + √15)

4 + √15

= ----------------------

(4)^2 - (√15)^2

4 + √15

= -----------------

16 - 15

= 4 + √15

1

Therefore, ---- = 4 + √15

x

1

Now , x + ----

x

= 4 - √15 + 4 + √15 ( -√15 + √15 canceled)

= 4 + 4

= 8

HOPE YOU HAVE UNDERSTOOD

THANK YOU