[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vp / vr / w / wg / wsg / wsr / x / y / ] [Home]
4chanarchives logo

Sorry for a stupid question, just haven't dealt with maths in quite a while,


Thread replies: 8
Thread images: 1

File: new.png (9KB, 667x184px) Image search: [Google] [Yandex] [Bing]
new.png
9KB, 667x184px
Sorry for a stupid question, just haven't dealt with maths in quite a while, would be grateful if someone could explain this school grade math equation to me. Pic related.
>>
>>7795863
Did you ever learn how to do plane rotations?
>>
>>7795870
yea.. which was quite some time ago..
>>
>>7795863
Im thinking definite integral and playing around with sinhx and coshx maybe?
>>
anyone?
>>
replace y with (x+y)/sqrt(2) and y with (x-y)/sqrt(2)
use these new variables
>>
>>7795935
can you explain the reasoning? what is the full formula with cos and sin?
>>
>>7796006
x= xcos theta - y costheta
y = x sintheta + y cos(theta)

or something like that. Look up quadratic forms (matrices) and rotations of (x, y) column vectors.

The formula for what you have is z = Tranpose(v) tranpose(R) [1/a^2 0 0 -1/b^2] R v

where v is [x y] in column form and R is your rotation matrix and [1/a^2 0 0 -1/b^2] is an obvious 2x2 Matrix.
Thread replies: 8
Thread images: 1
[Boards: 3 / a / aco / adv / an / asp / b / biz / c / cgl / ck / cm / co / d / diy / e / fa / fit / g / gd / gif / h / hc / his / hm / hr / i / ic / int / jp / k / lgbt / lit / m / mlp / mu / n / news / o / out / p / po / pol / qa / r / r9k / s / s4s / sci / soc / sp / t / tg / toy / trash / trv / tv / u / v / vg / vp / vr / w / wg / wsg / wsr / x / y / ] [Home]

All trademarks and copyrights on this page are owned by their respective parties. Images uploaded are the responsibility of the Poster. Comments are owned by the Poster.
If a post contains personal/copyrighted/illegal content you can contact me at [email protected] with that post and thread number and it will be removed as soon as possible.
If a post contains illegal content, please click on its [Report] button and follow the instructions.
This is a 4chan archive - all of the content originated from them. If you need information for a Poster - you need to contact them.
This website shows only archived content and is not affiliated with 4chan in any way.
If you like this website please support us by donating with Bitcoin at 1XVgDnu36zCj97gLdeSwHMdiJaBkqhtMK