Question

If a-1/a=3, find a^4+1/a^4

Answer 1

Answer:

(a-1/a)^2=a^2+1/a^2-2

(3)^2=a^2+1/a^2-2

9+2=a2+1/a^2

11=a^2+1/a^2

(a^2+1/a^2)^2=a^4+1/a^4+2

(11)^2=a^4+1/a^4+2

121-2=a^4+1/a^4

119=a^4+1/a^4