Question

please need fast only no2 please help me out of this problem

Answer 1

8. (ii)

Given x = 2√3 + 2√2

Then, 1/x = 1/(2√3 + 2√2)

  We rationalise the denominator by multiplying the conjugate irrational number (2√3 - 2√2) to both the numerator and the denominator.

= (2√3 - 2√2)/{(2√3 + 2√2)(2√3 - 2√2)}

= (2√3 - 2√2)/(12 - 8)

= (2√3 - 2√2)/4

So, x + 1/x

= (2√3 + 2√2) + (2√3 - 2√2)/4

= (8√3 + 8√2 + 2√3 - 2√2)/4

= (10√3 + 6√2)/4

= (5√3 + 3√2)/2