Question

if x +1/x =4 find x^3 +1/x^3​

Answer 1

Answer:

Do cubing both sides than you can get answer 61

Answer 2

Answer:

x + 1/x=4....x^3+ 1/x^3

okkk....so let's solve it here's your solution brother !

Step-by-step explanation:

Formula of x^3+ 1/x^3=(x + 1/x) (x^2 - 1 + 1/x^2)

Now we know the value of x + 1/x which is 4 (given)

but we don't know the value of x^2 + 1/x^2

so let's find it by using formula

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

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

=x^2 + 1/x^2=16 - 2 = 14

So we got the value of x^2 + 1/x^2

Now putting it in formula,we get :

x^3+ 1/x^3= 4 (14 - 1)

{since x + 1/x = 4 and x^2 + 1/x^2 =14}

x^3+ 1/x^3=4*13

x^3+ 1/x^3=52.

Hope u understood...