>>12733196To be more accurate,
Your answer is is sqrt(2)/sqrt(11)
And the textbook's is sqrt(22)/11 which is merely yours with the numerator and denominator multiplied by sqrt(11), they are both ~0.426
Like the anon above me pointed out, they just rationalised the denominator, since its generally disliked to have an irrational denominator and as you'll find out later, an imaginary denominator.
