Question

if [x^2]+[1/x^2]=7 then [x]+[1/x ]= ?​

Answer 1

Step-by-step explanation:

if x²+1/x²=7

then (x+1/x)²-2×x²×1/x²=7

or (x+1/x)²-2=7

or (x+1/x)²=7+2

or (x+1/x)²=9

or x+1/x= root 9

so x+1/x = 3

Answer 2

Answer:

3

Explanation:

1. (x+1/x)^2 = x^2 + 1/x^2+2*x*1/x
2. (x+1/x)^2 = 7+2
3. (x+1/x)^2 =9
4. x+1/x = ✓9
5. x+1/x =3