(Continuation from yesterday)

The followings are impossible without the concept of quadratic equations.

- Estimation of surface area of a land with distance.

- Estimation of area within earshot when shouting.

- Concept of a danger of the person's body, killing oneself by jumping

Without exponential functions,

- Understand of whole serious problems with the declining birth rate and aging population.

To begin with, without trigonometric function, not to say,

- Building houses

and

- Making shelves by DIY

It should become a dangerous action.(hurt in falling objects)

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I had already told the following stories again and again,

When I was forced to join a kind of presentation about pyramid scheme, I crashed the orientation practically with talking "the business model you said now, become destroyed, if only you turn the cycles several times."

When I discussed a sale person for gas powered hot water heater, he run away before I asked him about my merits to exchange the gas machine with showing the calculation result about depreciation cost.

According to the solar panel, when the sale person told me about the incentive rule of Tokyo district, I asked him "Do you really believe in you mind, the rule is going to continue for more than 30 years ?" and I have never seen him after that.

Well, how to say,

Mathematics and numeral are kinds of essential tools, not to be tricked in your life.

(To be continued)