(Continuation from yesterday)

Well, let us think why "trigonometric function" is handled so roughly, even it has much effect on from religions, philosophy to national strategy.

The reasons are,

(1)we cannot feel usability in our daily life,

(2)we feel easy to decide "trigonometric function" is just a tool for specialists of different world.

And the cause is

"How Mathematics Education should be"

It all comes down to the fact that.

However, as far as this "mathematics education", I have already been stated so far, I will skip this time.

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What I would like to claim this time, is

""object oriented" education of trigonometric functions is necessary"

Whether it is a quadratic function, an exponential function, a logarithmic function, or a trigonometric function,

Instead of "tinkering with mathematics" as in mathematics education now,

In order to understand that the actual values which are thrown into those functions, and come out, are "delicious"

"Mathematical cooking practice"

should be needed, I think.

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The present mathematics education is,

- to present just contents(nutrients and calories) of ingredients of cooking,

- to teach just how to cook (simmering time, ignition)

- to say just "I taught the basics of cooking with this. Therefore, anyone can cook"

- to just leave

Indeed, the current mathematics education is "cooking lessons that neither" make "nor" eat "by oneself.

With this, it is natural to come "the opinion that trigonometric functions are unnecessary".

(To be continued)