Graphs.

[cindyy]

1. square root x² -36

2. square root 16 - x²

Why isn't the first one a semi circle?

[TrueTears]

1. is the semicircle.

When in doubt let y = f(x) and rearrange.

2. semi circle radius 4.

[cindyy]

so if the second one was square root x²-16 it wouldn't be a semicircle?

[the.watchman]

so if the second one was square root x²-16 it wouldn't be a semicircle?

That's right!
Think about the domain and the direction of the graph!

[TrueTears]

so if the second one was square root x²-16 it wouldn't be a semicircle?

no.

try showing it's not a semicircle

[cindyy]

okay, thank you both!

[Cthulhu]

Try showing that if the methods universe would explode into a billion pieces and the specialist universe would be haha'ing

[TrueTears]

Try showing that if the methods universe would explode into a billion pieces and the specialist universe would be haha'ing

LOL ohh nooooooo

[the.watchman]

Try showing that if the methods universe would explode into a billion pieces and the specialist universe would be haha'ing

I don't get you...

[TrueTears]

x^2-16<0

rt[x^2-16] ~!@~!@~!#~!#

[the.watchman]

x^2-16<0

rt[x^2-16] ~!@~!@~!#~!#

Ahhh lol!!! What would maths be like without complex numbers

[cindyy]

i still dont get it :S Lawwwl

[TrueTears]

ok.

[stonecold]

ahh you've confused me cindy!

is it basically that you can't take the square root of a negative number?

[the.watchman]

You mean the thing?

First, check out the domain, there's no way a semicircle can have that sort of domain

Second, there are two arms to this graph