Wednesday, November 10, 2010

`(2/x - 3y)^5` Use the Binomial Theorem to expand and simplify the expression.

You need to use the binomial formula, such that:


`(x+y)^n = sum_(k=0)^n ((n),(k)) x^(n-k) y^k`


You need to replace `2/x` for x, 3y for y and 5 for n, such that:


`(2/x-3y)^5 = 5C0 (2/x)^5 +5C1 (2/x)^4*(-3y)^1+5C2 (2/x)^3*(-3y)^2 + 5C3 (2/x)^2 (-3y)^3 + 5C4 (2/x)(-3y)^4 + 5C5 (-3y)^5`


By definition, nC0 = nCn = 1, hence `5C0 = 5C5 = 1.`


By definition nC1 = nC(n-1) = n, hence `5C1= 5C4 = 5.`


By definition `nC2 = n(n-1)/2` , hence `5C2= 5C3 = 10.`


`(2/x-3y)^5 = 32/x^5 - (240y)/x^4 + (720y^2)/x^3 - (1080y^3)/x^2 + (810y^4)/x - 243 y^5`


Hence, expanding the expression using binomial theorem yields `(2/x-3y)^5 = 32/x^5 - (240y)/x^4 + (720y^2)/x^3 - (1080y^3)/x^2 + (810y^4)/x - 243 y^5.`

No comments:

Post a Comment

How does the choice of details set the tone of the sermon?

Edwards is remembered for his choice of details, particularly in this classic sermon. His goal was not to tell people about his beliefs; he ...