Question

if X+1/X=20 find the value of x^2+1/x^2​

Answer 1

Answer:

squaring both sides

(x+1/x)^2=(20)^2

x^2+1/x^2+2×x×1/x=400

x^2+1/x^2=400-2=398

x^2+1/x^2=398

Answer 2

Answer:

Consider (x – 1/x) = 9 Squaring on both the sides, we get [x – (1/x)]2 = 32 x2 – 2 (x) (1/x) + (1/x2) = 9 x2 – 2 + (1/x2) = 9 Therefore, x2 + (1/x2) = 9 + 2 = 11