# Microsoft's advanced trigonometry

• This screenshot is from the "Power Calculator" available as a free download from Microsoft. It seems that Microsoft has quite an unique way of calculating sin(x).

• I'm trying to figure out what's happening here. Normally, when calculating a sin function, you confine the inputs to be between negative pi and positive pi and do a polynomial approximation. But to limit it to be from -6.5 pi to +6.5 pi? It's almost like it's between -2pi * pi and +2pi * pi or something odd like that. WTF?

•  Nobody will ever need to calculate sin(x) for values of x where abs(x) > 20.  That's just a fact.

• It almost looks as if they are using a Taylor expansion for computing sin(x), if it wasn't for the fact that with insufficient accuracy, the "edges" tend to go separate ways (+/-Infinity). Pretty stupid thing to do without exploiting modularity/circularity of the argument x, since sin(x) requires insanely high orders of expansion (talk about polynomial complexity!) if you want to compute large values of x. With an order of n=13 you can barely approximate the first period, let alonea range of (-10,10) ...

•  So as far as the Power Calculator is concerned, x is Bart Simpson?

•  6.40πs ought to be enough for anybody?

• @HavocHQ said:

So as far as the Power Calculator is concerned, x is Bart Simpson?
Looks like the original Bart Simpson, not the current one.

• oddly, this only seems to apply for the graphing, the actual calculations seem to be just fine.

sin(40) = 0.7451131604793487869877094026363443422394990400302087249891402409

sin(30) = -0.9880316240928617899877489072944581504868079482212127883664291343

• @DescentJS said:

oddly, this only seems to apply for the graphing, the actual calculations seem to be just fine.
I'm sure that in order to recycle precious CPU cycles, the "sin(x)" function isn't rendered at every request. You're probably served a pre-rendered image from a central webserver. A previous user created the graph for the function using these limits and that one got uploaded to the central webserver and stored in a hashtable using "sin(x)" as the key.

Enterprisy. I'm sure it happens all the time.

• @bjolling said:

@DescentJS said:

oddly, this only seems to apply for the graphing, the actual calculations seem to be just fine.
I'm sure that in order to recycle precious CPU cycles, the "sin(x)" function isn't rendered at every request. You're probably served a pre-rendered image from a central webserver. A previous user created the graph for the function using these limits and that one got uploaded to the central webserver and stored in a hashtable using "sin(x)" as the key.

Enterprisy. I'm sure it happens all the time.

So then the real problem is that they forgot the wooden table?

Perhaps they were trying to recreate wood grain?

• @DescentJS said:

@bjolling said:

@DescentJS said:

oddly, this only seems to apply for the graphing, the actual calculations seem to be just fine.
I'm sure that in order to recycle precious CPU cycles, the "sin(x)" function isn't rendered at every request. You're probably served a pre-rendered image from a central webserver. A previous user created the graph for the function using these limits and that one got uploaded to the central webserver and stored in a hashtable using "sin(x)" as the key.

Enterprisy. I'm sure it happens all the time.

So then the real problem is that they forgot the wooden table?

Perhaps they were trying to recreate wood grain?

You sir have insulted the Wooden Table. I demand satisfaction and challenge you to a duel

• On a wooden table?

• @menta said:

On a wooden table?
God has given Belgarion, King of the Britons, and his Knights of the Wooden Table a task to make them an example in these dark times. Together with Sir Store-Pee-a-Lot and his merry fool MasAsshatSoftware they have been searching for the Holy Grail ever since the Lady of the Lake, her arm clad in the purest shimmering samite held
aloft ExcaliMorbs from the bosom of the water, signifying by divine
providence that Belgarion was to carry ExcaliMorbs to strike fear in the hearts of the trolls that dwell on these forums.

• @bjolling said:

@menta said:
On a wooden table?
God has given Belgarion, King of the Britons, and his Knights of the Wooden Table a task to make them an example in these dark times. Together with Sir Store-Pee-a-Lot and his merry fool MasAsshatSoftware they have been searching for the Holy Grail ever since the Lady of the Lake, her arm clad in the purest shimmering samite held aloft ExcaliMorbs from the bosom of the water, signifying by divine providence that Belgarion was to carry ExcaliMorbs to strike fear in the hearts of the trolls that dwell on these forums.
Good job making everyone not mentioned in this reply feel left out!

• @Welbog said:

@bjolling said:

@menta said:
On a wooden table?
God has given Belgarion, King of the Britons, and his Knights of the Wooden Table a task to make them an example in these dark times. Together with Sir Store-Pee-a-Lot and his merry fool MasAsshatSoftware they have been searching for the Holy Grail ever since the Lady of the Lake, her arm clad in the purest shimmering samite held aloft ExcaliMorbs from the bosom of the water, signifying by divine providence that Belgarion was to carry ExcaliMorbs to strike fear in the hearts of the trolls that dwell on these forums.
Good job making everyone not mentioned in this reply feel left out!

Especially considering that you're slightly Britisher than all those guys.

• @Welbog said:

Filed under: , sadface.jpg, T_T, , ):
Oh no! Did I do that? By the way, I was digging through the archives and read the "Why do people hate Vista?" thread and I was really moved by the bravery displayed by Russ. He was not in the least bit scared to be mashed into a pulp. Brave fool MPS

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