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09'ers so you think you can do maths? (1 Viewer)

Kurwa

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I see you guys/girls seem to complain way too much over maths, so i have decided to make a thread similar to "4unit revising game" but this one will consist of questions that will test you knowledge on "maths"...

So here it comes :jedi:

question 1) Consider the quadratic equation

x^2-(2cos@)x+1 =0

which has roots alpha and beta...

find an expression for alpha and beta and hence prove that alpha^10 + beta^10 = 2cos(10@)

it will be a good practice for your trails + hsc xD
 

Timothy.Siu

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AB=1
A+B=2cos @
A=1/B
B2-2cos@ B+1=0
B=[2cos@ +- root(4cos2@-4)]/2
=cos@+-root(i^2(1-cos^2 @))
=cos@+-i|sin @|

therefore
B=cos@+isin@
A=cos@-isin@
A^10+B^10=(cos@+isin@)^10+(cos@-isin@)^10
=cos10@+isin10@+cos10@-isin10@
=2cos 10@
 

Kurwa

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mc yeh i did do 4unit..

relax ladies the first one is usually the easy one =]

plus im not gaining notthin from this im doing uni maths xD
 

Kurwa

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round 2-

Prove that (1+itan@)^n + (1-itan@)^n = 2sec^n@cosn@

Hence prove that

Re(1+itan(pi/8))^8 = 64(17-12root2)

as you can see i dont target specific chapters!
 

Kurwa

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AB=1
A+B=2cos @
A=1/B
B2-2cos@ B+1=0
B=[2cos@ +- root(4cos2@-4)]/2
=cos@+-root(i^2(1-cos^2 @))
=cos@+-i|sin @|

therefore
B=cos@+isin@
A=cos@-isin@
A^10+B^10=(cos@+isin@)^10+(cos@-isin@)^10
=cos10@+isin10@+cos10@-isin10@
=2cos 10@
make life easier by using quadratic formula xD

its alot better than using alpah + beta = ...
 

vds700

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round 2-

Prove that (1+itan@)^n + (1-itan@)^n = 2sec^n@cosn@

Hence prove that

Re(1+itan(pi/8))^8 = 64(17-12root2)

as you can see i dont target specific chapters!
have i stumbled across the general maths forum??
 

samthebear

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maybe it's because no one really gives a toss about this thread and only really want to post on here to ridicule you. Spend your time doing something more productive =] you deffinately deserve to do something worth your while.
 

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