Scratch

johndo77 · 2010-12-22 22:31:28

Try it on Scratch! It makes an error!

I tried it on a calculator. It has an answer.

Last edited by johndo77 (2010-12-22 22:31:56)

Shadowed1 · 2010-12-22 22:54:51

Ooh, it does smile

hmnwilson · 2010-12-22 23:50:17

It's 1.99520041... why would Scratch say that's an error?

mathematics · 2010-12-23 01:14:52

I know why but this is kind of difficult to explain actually... I'll try to.

Trigonometric arguments can be in either degrees or radians.
When it is in degrees: tan((-90)°) = complex infinity
When it is in radians: tan(-90) = -tan(90) = 1.9952004122082420252873530763796023761917715543914539347143...

Scratch takes trigonometric arguments in degrees, while your calculators take trigonometric arguments in radians.

what-the · 2010-12-23 02:25:05

http://en.wikipedia.org/wiki/Radian

deg = rad * (180/ pi)

Degrees and Radians are different. Now who ever has a calculator make sure that you leave it on degrees. Usually represented by "d" on a scientific calculator. Unless a question says it in radians don't use it as you'll get questions wrong.

On many Casio scientific calc's degrees is default. To restore default settings check your manual.

My scientific is Shift --> 9 (CLR) --> 1 (Setup) --> =

Also I can change to and from rads by Shift --> Setup

Harakou · 2010-12-23 09:38:02

Simple. tan(-90) = tan(270) = sin(270)/cos(270) = -1/0 = Error

johndo77 · 2010-12-23 10:03:22

Thanks! I thought it might have something to do with that, but I'm not very good at trigonometry.

Is there a way to turn Scratch from degrees to radians?

Harakou · 2010-12-23 11:29:28

johndo77 wrote:
Thanks! I thought it might have something to do with that, but I'm not very good at trigonometry.

Is there a way to turn Scratch from degrees to radians?

I don't think so, but you can always convert degrees to radians with this equation:

Code:

radians = (degrees * pi)/180
degrees = radians * (180/pi)

johndo77 · 2010-12-23 21:28:07

Harakou wrote:
johndo77 wrote:
Thanks! I thought it might have something to do with that, but I'm not very good at trigonometry.

Is there a way to turn Scratch from degrees to radians?
I don't think so, but you can always convert degrees to radians with this equation:
Code:
radians = (degrees * pi)/180
degrees = radians * (180/pi)

Cool.

ScratchReallyROCKS · 2010-12-24 13:56:43

mathematics wrote:
I know why but this is kind of difficult to explain actually... I'll try to.

Trigonometric arguments can be in either degrees or radians.
When it is in degrees: tan((-90)°) = complex infinity
When it is in radians: tan(-90) = -tan(90) = 1.9952004122082420252873530763796023761917715543914539347143...

Scratch takes trigonometric arguments in degrees, while your calculators take trigonometric arguments in radians.

That makes sense....let me try switching my calculator to degrees mode...

EDIT: Yep, you're right.

Last edited by ScratchReallyROCKS (2010-12-24 13:58:13)

MarioLuigi2009 · 2011-01-04 17:55:43

if you draw a graph using tangent of x, -90 is where it is straight up and down.

it's shaped like this:

Code:

     *

     |   
    /|    /
 .-' | .-'
/    |/
     |

* x:-90

Last edited by MarioLuigi2009 (2011-01-04 18:01:26)

Scratch

archived forums

#1 2010-12-22 22:31:28

Tangent of -90

#2 2010-12-22 22:54:51

Re: Tangent of -90

#3 2010-12-22 23:50:17

Re: Tangent of -90

#4 2010-12-23 01:14:52

Re: Tangent of -90

#5 2010-12-23 02:25:05

Re: Tangent of -90

#6 2010-12-23 09:38:02

Re: Tangent of -90

#7 2010-12-23 10:03:22

Re: Tangent of -90

#8 2010-12-23 11:29:28

Re: Tangent of -90

johndo77 wrote:

Code:

#9 2010-12-23 21:28:07

Re: Tangent of -90

Harakou wrote:

johndo77 wrote:

Code:

#10 2010-12-24 13:56:43

Re: Tangent of -90

mathematics wrote:

#11 2011-01-04 17:55:43

Re: Tangent of -90

Code:

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