17 Feb 2009 at 20:28 #1 crooked i crooked i Permabanned Joined 11 Jan 2009 Posts 252 Find the square roots of 3-4j Can anyone help with this? btw, j = square root(-1)
17 Feb 2009 at 20:43 #3 crooked i crooked i Permabanned OP Joined 11 Jan 2009 Posts 252 HOW did you manage that!
17 Feb 2009 at 20:52 #11 crooked i crooked i Permabanned OP Joined 11 Jan 2009 Posts 252 Vixen said: (a^2-b^2)+a*b*j - so 3 = a^2-b^2 and -4 = a*b EDIT: Think of it as factorising a quadratic - the roots will be of the form a+bj, so you just need to expand (a+bj)(a+bj) Click to expand... thats what i thought, but why do we do that. thats what confuses me, we are sqrting yet somehow i have to factorise. i mean yeah i could do that, and get my marks, but itll eat me till i know WHY thats what we do.
Vixen said: (a^2-b^2)+a*b*j - so 3 = a^2-b^2 and -4 = a*b EDIT: Think of it as factorising a quadratic - the roots will be of the form a+bj, so you just need to expand (a+bj)(a+bj) Click to expand... thats what i thought, but why do we do that. thats what confuses me, we are sqrting yet somehow i have to factorise. i mean yeah i could do that, and get my marks, but itll eat me till i know WHY thats what we do.
17 Feb 2009 at 21:00 #14 crooked i crooked i Permabanned OP Joined 11 Jan 2009 Posts 252 so wait, the question isnt square root, its the roots?