Alderweireld
2020-11-8 21:12:43
180度減返angle between plane ACP and ACD
著拖鞋紅衫短袖
2020-11-8 21:22:50
:^(
:^(
:^(
原來係咁，我本身hardcore地直接搵，計勁耐
:^(
或者就這樣吧
2020-11-9 00:50:27
有個位唔係好明 angle between two planes
definition上唔係唔會大過90度咩
:^(
Alderweireld
2020-11-9 07:35:00
plane理論上係可以infinitely extended
所以計個angle between two planes會拎細過90度嗰隻
但題目指明要angle between plane ACP and ACB
我諗佢用意係表明而家consider a finite region of a plane
正如angle ABC唔一定等於angle between AB and BC
The absolute value is required in above formulas, as the planes are not changed when changing all coefficient signs in one equation, or replacing one normal vector by its opposite.
However the absolute values can be and should be avoided when considering the dihedral angle of two half planes whose boundaries are the same line.