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Tutor question #1
Simplify the following:
\[\frac{1}{\sqrt2 + \sqrt3 + \sqrt5}\]
(conditions: pen, paper, no calculator, done in 2 minutes)
*
 one year ago
 one year ago
Tutor question #1 Simplify the following: \[\frac{1}{\sqrt2 + \sqrt3 + \sqrt5}\] (conditions: pen, paper, no calculator, done in 2 minutes) *
 one year ago
 one year ago

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CallistoBest ResponseYou've already chosen the best response.5
I got \[ \frac{2\sqrt3 + 3\sqrt2  \sqrt{30}}{12}\] Was that right?
 one year ago

apoorvkBest ResponseYou've already chosen the best response.0
HUNDRED PERCENT!!!!!!!!!!!!!
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
But it looks so messy...
 one year ago

bronzegoddessBest ResponseYou've already chosen the best response.0
i got something different: isn't it you cant have radicals under a fraction so you multiply by the conjugate?
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
That's what rationalise means
 one year ago

apoorvkBest ResponseYou've already chosen the best response.0
Not messy at all, this is the only way to go about it.
 one year ago

bronzegoddessBest ResponseYou've already chosen the best response.0
yes but if you multiply 1 by the conjugate pair you get the conjugate pair.. your numerator seems wrong..
 one year ago

bronzegoddessBest ResponseYou've already chosen the best response.0
otherwise can someone please show me a step by step to how you got that answer? and i'll show you what i did :)
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
luckily, I haven't deleted that.. \[(\sqrt2 + \sqrt3 + \sqrt5)(\sqrt2 + \sqrt3  \sqrt5)\]\[ = (\sqrt2 + \sqrt3)^25\]\[ = 2 + 3 + 2\sqrt65\]\[=2\sqrt6\] \[\frac{1}{\sqrt2 + \sqrt3 + \sqrt5}\]\[ = \frac{\sqrt2 + \sqrt3  \sqrt5}{(\sqrt2 + \sqrt3 + \sqrt5)(\sqrt2 + \sqrt3  \sqrt5)}\]\[ = \frac{\sqrt2 + \sqrt3  \sqrt5}{2\sqrt6}\]\[ = \frac{2\sqrt3 + 3\sqrt2  \sqrt{30}}{12}\]
 one year ago

RaphaelFilgueirasBest ResponseYou've already chosen the best response.0
\[1/(\sqrt{2}+\sqrt{3}+\sqrt{5})=1/(a+\sqrt{5})=(asqrt{5})/(a^{2}5)\] \[(\sqrt{2}+\sqrt{3}\sqrt{5})/(55+\sqrt{6})\] \[\sqrt{2}+\sqrt{3}\sqrt{5}/2\sqrt{6}=2.\sqrt{3}+2.\sqrt{2}\sqrt{30}/12\]
 one year ago

bronzegoddessBest ResponseYou've already chosen the best response.0
I ended at the second to last step... where did you get the 2 in front of the radicals if you are multiplying by 1?
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
see the first part of it..
 one year ago

RaphaelFilgueirasBest ResponseYou've already chosen the best response.0
55+2sqrt(6)*
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
@RaphaelFilgueiras The second term of the numerator is 3\sqrt{2} ?! \sqrt{18} = \sqrt{9 times 2} = 3\sqrt2 ...
 one year ago

bronzegoddessBest ResponseYou've already chosen the best response.0
okay, so the you rationalized the second to last line because of the radical at the bottom?
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
Of course! That's 'rationalise'
 one year ago

bronzegoddessBest ResponseYou've already chosen the best response.0
okay sorry, then you are right.. I just wanted to know where I went wrong...
 one year ago

RaphaelFilgueirasBest ResponseYou've already chosen the best response.0
no in my solution i put (55+sqrt(5))(WRONG) instead(55+2sqrt(5))
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
Sorry, but I don't know what you're doing.. No offense.
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
Do you mind retype it again?
 one year ago

RaphaelFilgueirasBest ResponseYou've already chosen the best response.0
i did same as you,but call(a=sqrt(2)+sqrt(3))
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
Okay, and the answer is the same?
 one year ago

CallistoBest ResponseYou've already chosen the best response.5
Okay, thanks everyone!!!
 one year ago
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