Question

X equal Root ( 13+2 root42 ).
X+1/X=?

Answer 1

Step-by-step explanation:

X=13+2✓42

squaring both sides

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

Now put the value of X

(13+2✓42)^2+(1/13+2✓42)^2 + 2

Now rationalize(1/13+2✓42)

you will get

(13+2✓42)^2+(13-2✓42)^2 + 2

So the answer

13×13+(2×2×42)+2×13×2✓42+13×13+(2×2×42)-2×13×2✓42+2

now after cancellation

169+168+169+168+2

676