Question

If a2+1/a=5 then find the value of a3+1/a3

Answer 1

Answer:

Step-by-step explanation:

a²+1/a² = 23

a²+1/a²+2 = 25

we know that , a²+b²+2ab = (a+b)²

(a+1/a)² = 25

a+1/a = √25 = 5

a³+1/a³ = (a+1/a)(a²+1/a²-ab)

as we know that a³+ b ³= (a+b)(a²+b²-ab)

a³+1/a³ = 5(23-1)

a³+1/a³ = 5(22) => 110

hope this helps