buddies plz help !!!

[InshallahAajaega]

im having truble in add maths binomial theorm !!!
need help in understanding the goddamn topic !!!!

 

[Alchemist4lyf]

Try these videos,:
The Khan Academy:
http://www.youtube.com/watch?v=Cv4YhIMfbeM
http://www.youtube.com/watch?v=-fFWWt1m9k0
http://www.youtube.com/watch?v=xF_hJaXUNfE

Patrick - Just Math Tutoring
http://www.youtube.com/watch?v=1pSD8cYyqUo
http://www.youtube.com/watch?v=TeE-ypKj8ZI

 

[scouserlfc]

Watch the KHAN academy one its awesome.

 

[InshallahAajaega]

yar i know how it works !!!
can u answr this question :
expand (1+2x)^20 - (1-2x)^20 upto term in x^5. use your result to evaluate (1.02)^20 - (0.98)^20 . !!!!!!!!!!!!!!!!!!!!!

 

[scouserlfc]

Actually i have not done this yet What i was talking was u could understand from there nut dont worry others might solve it,u have time right its not urgent then wait and ull get the answer,

 

[InshallahAajaega]

actually i dnt hav time!!!
plz yar sumbody solve this question!!!

 

[Nibz]

can u answr this question :
expand (1+2x)^20 - (1-2x)^20 upto term in x^5. use your result to evaluate (1.02)^20 - (0.98)^20 .

=> (1 + 2x)^20 = 1 + 20 (2x) + 190 (4x^2) + 1140 (8x^3) + 4845 (16x^4) + 15504 (32x^5).....
=> (1 - 2x)^20 = (just change the alternate signs) 1 - 20 (2x) + 190 (4x^2) - 1140 (8x^3) + 4845 ( 16x^4) - 15504 (32x^5)

Now the question states => (1 + 2x)^20 - (1 - 2x)^20 so subtract the x co-efficient from the x one; x^2 co-efficient from x^2 one and so on and so forth!
1-1 = 0
40x-(-40x) = 80x
760x^2 - 760x^2 = 0
9120x^3 - (-9120x^3) = 18240x^3
77520x^4 - 77520x^4 = 0
496128x^5 - (-496128x^5) = 992256x^5

So the first answer = 80x + 18240x^3 + 992256x^5....

for second part, it's simple. Make it like this => (1 + 0.02 )^20 - (1 - 0.02)^20
put 2x = 0.02 in your first expression!
You'l get 0.81.. something!

 

[InshallahAajaega]

hey!!!
i did the same thng but my answers 0.9 sumthn!!!
maybe theres fault in my calculator or sumthn!!!

 

[scouserlfc]

Have u got the correct mode in ur calculator required for solving this question maybe thats the problem