# Rationalising the denominator (C1 Surds)Watch

#1
I can do things like a/sqrt2

and using one conjugate a/1+srt2

but im stumped by this question i know i have to use conjugates on the top and bottom but im really unsure how

2 root3 + root2 / 3 root2 + root3 = root6/3

0
7 years ago
#2
I would rewrite as (?12 + ?2)/(?18 + ?3)
Then multiply by the conjugate, ie (?18 - ?3)

So we have ((?12 + ?2)/(?18 + ?3)) * ((?18 - ?3)/(?18 - ?3))

This reduces to (5?6)/15 = (?6)/3.

? = square root
1
7 years ago
#3
The way I did it:

(2root3 + root2)(3root2 - root3) all over (3root2 + root3)(3root2 - root3)

This when multiplied out gives: (6root6 - root6) all over 15

Then it's just gathering/simplifying to 5root6 over 15, and thus root6/3
1
#4
Thanks I understand it now I wasn't multiplying out properly but after a few more tries I got it <3
0
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