# LaTeX -- Practice/Test

• Jul 9th 2010, 07:50 PM
DeanSchlarbaum
LaTeX -- Practice/Test
Re: Multiplication w. Complex Number Involvement --

$(3\sqrt{-5})(-4\sqrt{-12})$

$(3)(i\sqrt{5}) \times (-4)(i)(\sqrt{4 \times 3})$

$(3i)(\sqrt{5}) \times (-4i)(2)(\sqrt{3})$

$(3i)(\sqrt{5}) \times (-8i)(\sqrt{3})$

$(-24)(i^2)(\sqrt{15})$

$(-24)(-1)(\sqrt{15})$

$24\sqrt{15}$

$\sqrt{15} \approx 3.873$

$24 \times 3.873 \approx 92.952$

So, $(3\sqrt{-5})(-4\sqrt{-12}) \approx 92.952$ . . .

Ain't that sometin!! In a million years I would never have guessed that $(3\sqrt{-5})(-4\sqrt{-12})$ is equal to that.
Complex numbers play "funny" tricks on old neurons! My parents should have started me on this when I was six! Maybe even three!
• Jul 9th 2010, 07:53 PM
Chris L T521
Quote:

Originally Posted by DeanSchlarbaum
Re: Multiplication w. Complex Number Involvement --

$$(3\sqrt{-5})(-4\sqrt{-12})[\math] [tex](3)(i\sqrt{5}) x (-4)(i)(\sqrt{4x3})[\math\ [tex](3i)(\sqrt{5}) x (-4i)(2)(\sqrt{3}) [\math] [tex](3i)(\sqrt{5}) x (-8i)(\sqrt{3}) [tex](-24)(i^2)(\sqrt{15})[\math] [tex] (-24)(-1)(\sqrt{15})[\math] [tex] 24\sqrt{15}[\math] It should be [tex]$$, not $$[\math]; hence why your code was not compiled into the images. • Jul 9th 2010, 08:35 PM DeanSchlarbaum Quote: Originally Posted by Chris L T521 It should be [tex]$$, not [tex][\math]; hence why your code was not compiled into the images.

Chris: Thank you. However, I figured that out (somehow) by myself before I saw your reply to my Post. When I first joined MHF I printed a Post titled "LATEX on MHF." In it it shows the bracketed "math" with BOTH forward facing and back facing slashes. I think the newer tutorial corrects that. Again, thanks -- I am new to Forum, right now formating formulas with LaTeX seems very cumbersome and difficult, and I need all the help I can get!