SRL Archive - Mathematics

I dont know how to do alpha so im gonna do $ for alpha

Sin $ = cos $ False?

Sin (90 - $) = sin $

Sin (90 + $) cos $

Sin (-$) = cos($)

Sin (180 + $) = Sin($)

-> True when $ = pi/2
-> True
-> False (I think)
-> False
-> False {sin(2pi + $) == sin($)}

From: Nava2
-> True when $ = pi/2
-> True
-> False (I think)
-> False
-> False {sin(2pi + $) == sin($)}

For the second one (Sin (90 - $) = sin $), sin(90 - 30) = sin(30) is not true??

You're right, idk what I'm thinking of..

From: Simtoon
I dont know how to do alpha so im gonna do $ for alpha

Sin $ = cos $ False?

Sin (90 - $) = sin $

Sin (90 + $) cos $

Sin (-$) = cos($)

Sin (180 + $) = Sin($)

First is true while $ = k*pi/4, where k is any odd integer.
Second is true while $ = pi/4 + k*pi, where k is any even integer.
Third is true.
Fourth is true while $ = k*pi, where k is any even integer.
Fifth is false.

From: Cigue
First is true while $ = k*pi/4, where k is any odd integer.
Second is true while $ = pi/4 + k*pi, where k is any even integer.
Third is true.
Fourth is true while $ = k*pi, where k is any even integer.
Fifth is false.

The fourth one doesn't seem right. sin(-2*pi) != cos(2*pi). 3*pi/4 + n*pi seems to be a valid answer (though there may be others).

for the second one

what if $ = 45 then its true


now keep in mind that I don't remember a lot of this stuff so no hate

From: Method
The fourth one doesn't seem right. sin(-2*pi) != cos(2*pi). 3*pi/4 + n*pi seems to be a valid answer (though there may be others).

Why are you timing by pi?

From: Simtoon
Why are you timing by pi?

Radians.

Degrees suck, its a stupid system and radians make MUCH more sense. Also, once you get into harder mathematics, you *can't* use degrees ;)

From: Nava2
Radians.

Degrees suck, its a stupid system and radians make MUCH more sense. Also, once you get into harder mathematics, you *can't* use degrees ;)

Lol, not in everyday life.
"How wide is that angle?"
"It's about 45 degrees" vs. "It's about Pi/4"

"The car turned in a 120 degree angle" vs.
"The car turned in a 2/3 Pi angle"

Which make more sense :rolleyes:

Ofcourse when talking about real mathematics radians are the way to go, but you can't say that radians make more sense.

Not to mention he's explicitly using degrees in his question.

From: marpis
Lol, not in everyday life.
"How wide is that angle?"
"It's about 45 degrees" vs. "It's about Pi/4"

"The car turned in a 120 degree angle" vs.
"The car turned in a 2/3 Pi angle"

Which make more sense :rolleyes:

Ofcourse when talking about real mathematics radians are the way to go, but you can't say that radians make more sense.

What if you were brought up so you knew what 2/3 pi meant intuitively and only learnt the idea of degrees in high school?

From: The Claw
What if you were brought up so you knew what 2/3 pi meant intuitively and only learnt the idea of degrees in high school?

Lol what's that supposed to mean? Everyone teaches radian measure based on the idea that pi is 180 degrees…so the radian should succeed the degree =.=

I mean degrees and radians are two ways of describing the same thing, and the reason people think in degrees is because thats society's prescribed way of measuring. You said it yourself - "everyone teaches radian based on degrees"

From: The Claw
I mean degrees and radians are two ways of describing the same thing, and the reason people think in degrees is because thats society's prescribed way of measuring. You said it yourself - "everyone teaches radian based on degrees"

Yes but degrees can be expressed in a single integer, while radians always need the Pi and mostly a fraction number..

radians are for mathematics but degrees are for measurements.
astronomy, marksmanship and surveying all use degrees, arcminutes and arcseconds. But when they go off to do their maths, they all convert to radians.

From: marpis
Yes but degrees can be expressed in a single integer, while radians always need the Pi and mostly a fraction number..

Half a pie = Pi
Full pie = 2 *Pi
three quarters of a pie = 3/2 * Pi

That's WAY better for a toddler than going "this is 180, this is 360, this is 270"

From: Cigue
Half a pie = Pi
Full pie = 2 *Pi
three quarters of a pie = 3/2 * Pi

That's WAY better for a toddler than going "this is 180, this is 360, this is 270"

Just tell them that full pie = 360 degrees…then they'll figure out the rest on their own…

From: Santa_Clause
Just tell them that full pie = 360 degrees…then they'll figure out the rest on their own…

In before a generation completely made of pimps and hookers

(Trolling aside, the same applies for radians, plus when you know radians the functions of circle area and circonference become intuitive)

Sin $ = cos $ False? Of course its false…..

Sin (90 - $) = sin $ False

Sin (90 + $) cos $ True

Sin (-$) = cos($) False

Sin (180 + $) = Sin($) False