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pratu043
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How do you find the rationalising factor of root2 + root7  root10?
 2 years ago
 2 years ago
pratu043 Group Title
How do you find the rationalising factor of root2 + root7  root10?
 2 years ago
 2 years ago

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pratu043 Group TitleBest ResponseYou've already chosen the best response.0
dw:1344951900463:dw
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
multiply that by its conjugate @pratu043 what do you get?
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
By conjugate you mean: dw:1344952032255:dw
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
\[\large{(\sqrt{2}+\sqrt{7}\sqrt{10})(\sqrt{2}+\sqrt{7}+\sqrt{10})=?}\]
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
dw:1344952080072:dw
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
@pratu043 what do you get by multiplying that.. ?
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
How do you find the conjugate?
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
I only know how to find for binomial surds.
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
@pratu043 let the expression given be like this: \[\large{(\sqrt{2}+\sqrt{7})(\sqrt{10})}\]
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
I meant to say that: a+bc = (a+b)(c) right?
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
dw:1344952309566:dw
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
dw:1344952351465:dw What do you do with  root10?
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
dw:1344952415376:dw sorry
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
ok leave that for once... what will be the conjugate of a+b ?
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
right so let a = c+d and b = b now can u tell me what will be the new conjugate? : (c+d)+(b) conjugate = ?
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
(c+d)  (b)
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
right so what will be the conjugate of : \[\large{(\sqrt{2}+\sqrt{7})(\sqrt{10})}\]
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
dw:1344952630671:dw ok, I got the conjugate part.
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
right now : multiply this conjugate with original expression
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
dw:1344952686106:dw right?
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
good so we have: \[\large{2\sqrt{14}1}\] now:(√2 + √7  √10)[(√2 + √7 + √10) (2√14 + 1)] do this
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
dw:1344952926110:dw
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
But why should we do this?
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
it is a step towards the answer
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
also try to check that out pratu that u did: can that be more simplified?
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
@pratu043 you there?
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
sorry yes i am there.
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
do you mean that we should try and convert the irrationals in that expression to mixed surds?
 2 years ago

pratu043 Group TitleBest ResponseYou've already chosen the best response.0
I think I can handle it on my own now, thanks!!
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
(√2 + √7  √10)[(√2 + √7 + √10) (2√14 + 1)] \[\large{(\sqrt{2}+\sqrt{7}\sqrt{10})(\sqrt{2}+\sqrt{7}+\sqrt{10})(2\sqrt{14}+1)}\] \[\large{(9+2\sqrt{14}10)(2\sqrt{14}+1)=(2\sqrt{14}1)(2\sqrt{14}+1)=561=55}\]
 2 years ago

mathslover Group TitleBest ResponseYou've already chosen the best response.3
nice to hear best of luck
 2 years ago
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