Question

If x + 1/x = 5, find the values of each of the following:
X
(i) x2 +1/x2
(ii) x4 +1/x4​

Answer 1

Answer:

x+1/x=5

squaring on both sides

( x+1/x) ^2 =5^2

x^2+(1/x) ^2+2(x) (1/x) =25

x2+1/x2=25-2

=23

nw again squaring

x4 +1/x4 +2x2*1/x2=23*23

x4+1/x4=529-2=527