Apple mobile phone IOS comes with a scientific calculator unpopular function to use

foreword

The incident is like this. A few days ago, someone wanted to buy a slope pillow. The slope pillow is a right triangle. It is known that the length of the short side is , and the 14CMlength of the long side is 80CM. He wants to know the degree of the slope. I said this is not very simple ? Calculate $I\text{'}msafe(\_\frac{14}{80})$ is not on the line?

Then I open the Apple Calculator, switch to the scientific calculation mode, and enter 14, $÷$ ,80,tanh, looking at the result makes me a little confused, why is it 0.17323525...? This slope is definitely not right, I should have used it wrong, so I spent a little time researching how to use this scientific calculation.

Angles and radians

There is one in the lower left corner of the calculator Rad, click it and it will become Deg, this is the abbreviation of RADyes Radian, which means " radian system (a unit for measuring the size of an angle, 30°=π/6,60°=π/3,90° =π/2,180°=π)", DEGis the abbreviation of " Degree", which means "angle system", you should pay attention to this calculation.

Definition of radians

tanhhyperbolic tangent function

Then I checked Apple's documentation that tanh is a hyperbolic tangent function: $tenglish\left(x\right)=\frac{e^x-e^{-x}}{e^x+e^{-x}}$, not the arctangent function we want

$ta{n}^{-1}$ arctangent function

There is a 2 nd 2^{nd} at the top left of the computer$2^{nd}$ , we click, and tan − 1 tan^{-1}appears$ta{n}^{-1}$ , this is the function we want

and then input14,$÷$ 、80、$ta{n}^{-1}$ , the result is nearly 10°, which should be correct.

Rand, EEfunction,x!

Rand is to generate a random number between (0,1)

EE是：$x\times 10^y$ , for example, if we want to input 20 million, we can input 2, EE, 6

x! is the factorial $x!=1\times 2\times 3\times ...\times x$

mc、mc+、mc-、mr

These four are mainly used to operate the memory value, and the default value of the memory value is 0

• mc(Memory Clear) Used to clear digital values ​​stored in memory
• m+(Memory Plus) Used to add the currently displayed digital value to the digital value stored in memory
• m-(Memory Minus) is used to subtract the currently displayed digital value from the digital value stored in the memory
• mr (Memory Recall) is used to display the digital value stored in the memory

For example, if we want to calculate (1+2+3+4)-(1 2 3*4),
we can press 1 + 2 + 3 + 4 m+ 4 x! m- mr
where 1+2+3+4 is equal to 10 and press The next m+ will be 10 memory, $4！=1\times 2\times 3\times 4=24$ , press m- to memorize 10-24=-14, finally press mr to display -14, and finally press mc to clear the memorized value.

$x^y和y^x$

This is because the sequence is different, for example, to calculate $2^3$ , you can press 2,$x^y$ , 3 can also press 3,$y^x$、2

Summarize

This article mainly introduces the functions that are not commonly used on the Apple Calculator. I don’t usually operate seemingly simple events. If I operate them suddenly, the result is different from what I predicted. Difficult , so we still have to make progress on paper, but never know that this matter has to be practiced .