Question

If (x +1/x)²= 3, find x³+1/x³​

Answer 1

Answer:

18

Step-by-step explanation:

So we start solving like:

x+1x=3  

(x+1x)3=33  

x3+3.x2.1x+3.x.1x2+1x3=27  

(x3+1x3)+3.x2.1x+3.x.1x2=27  

x3+1x3+(3x+3x)=27  

x3+1x3+3(x+1x)=27  

x3+1x3+3×3=27  

x3+1x3+9=27  

x3+1x3=18  

Therefore the answer is 18