| woobster | thats 2x^2 + 8x + 11 |
| art1k | vertex form? i need to make y=2x^2+4x+7 vertex form |
| woobster | 2(x+1)^2 + 5 |
| art1k | now would you be so kind as to explain |
| woobster | just expand it |
| t35t0r | anyone know any interesting recent papers on algorithms? |
| |seb| | % Expand[a (x+h)^2 +k] |
| mbot | |seb|: a*h^2 + k + 2*a*h*x + a*x^2 |
| john_sheu | ysics |
| Uncountable | what does the notation f|X mean, where f is a function and X is a set (a topology, actually)? i've seen it in two places in the book, and on both places, it's been f|X:X->Y, so I'd guess it means that f|X is f restricted to the domain of X, is that right? |
| woobster | % Expand[2(x+1)^2 + 5] |
| mbot | woobster: 7 + 4*x + 2*x^2 |
| woobster | Uncountable: well isnt that the same as f(x) ? |
| art1k | woobster, may I pm you? |
| |Steve| | Uncountable: Yes. |
| Uncountable | woobster: no, since the domain isn't X for f in these cases |
| woobster | oh the range is x? |
| Uncountable | |Steve|: okay, great! :) |
| art1k | what steps do i take to write the following equation in vertex form: y=2x^2+4x+7 |
| |Steve| | Usually it'll be f|_X : X -> Y, but some authors don't use a subscript. art1k: Complete the square? |
| art1k | yes how is that done i have bits and pieces of the process |
| woobster | 2(x+1)(x+1) + 5 |
| |Steve| | y = 2(x^2 + 2x) + 7 = 2(x^2 + 2x + 1 - 1) + 7 = 2(x^2 + 2x + 1) + 5 = 2(x+1)^2 + 5. |
| art1k | okay im going to write that down see if it makes more sense while i do, is it possible to type the quadratic formula? it's going to look different typer typed* |
| |Steve| | I'm not sure I follow you. |
| art1k | nevermind i think i got it |
| TRWBW | art1k: ax^2+bx+c=0 => x=(-b+sqrt(b^2-4ac))/(2a) or x=(-b-sqrt(b^2-4ac))/(2a) |
| art1k | yup thats it thanks |
| |Steve| | Oh, you just wanted someone to type it for you? |
| art1k | i couldnt remember it |