Question

if x = 2-root 3 then find the value of
x²+1/x²-2

​

Answer 1

Answer:

-2

Step-by-step explanation:

x = -2 - root(3)

squaring both sides

(x)^2 = 2-root(3)^2

x^2 = 7-4root(3) -------- (i)

x^2 + 1/x^2 - 2 --------- (ii)

putting (i) in (ii), we get

7-4root(3) + 1/7-4root(3) - 2

upon rationalizing 1/7-4root(3), we get

7 - 4root(3) + 7 + 4root(3) - 2

upon solving, we get answer as -2