Question

if x+1/x=2root10 and x-1/x=6
then
X4 + 1/x4=?
btw X4 is x to the power 4

Answer 1

Answer:

(x+1/x)^2 = (2*10^1/2)^2= 4*10=40

x^2+1/x^2= 40-2=38

(x^2+1/x^2)^2 = 38*38

x^4+1/x^4=38*38 - 2= 1442