Using an opensource app, Sensi -Shake to open app, my terminal emulator is opened each time I shake my smartphone, there I run the bc command since I like bc more than the smartphone calculator.

In order to use bc as a scientific calculator, just run it as:

`bc -l`

It only works in radians, so you should learn how to convert radians to degrees. You may use a simple rule of three.

Consider that 180 degrees equals to 4*a(1)

## Variables

You can declare a variable straightforwardly:

a=5

Do not confuse with the following expression:

a==5 which is a logical evaluation that may return true or false.

## Scientific notation

I improvised the scientific notation with the following code in bc:

a=0

if (x>10000) {

while (x>=10) {

x=x/10

a=a+1 }

x; a

}

if (x<0.0001) {

while (x<1) {

x=x*10

a=a+1 }

x; -a

}

**The basic**

π | 4*a(1) |

e | e(1) |

nth(y) root: | e(l(x)/y) |

Square root: | sqrt(x) |

## Transcendental functions

Natural logarithm | l(x) |

Common logarithm | l(x)/l(10) |

**Trigonometric functions:**

sin | s(x) |

cos | c(x) |

tan | s(x)/c(x) |

sec | 1/c(x) |

ctg | c(x)/s(x) |

csc | 1/s(x) |

arctg | a(x) |

arcctg | 2*a(1)-a(x) |

arccsc | a(1/x) |

**Arccosine:**

if (x== 0) {

90 } else {

a(sqrt(1/(x^2)-1))

}

**Arcsine:**

if (x==1) {

90 } else {

a(sqrt(1/(1-(x^2))-1))

}

**Arc secant:**

There is not an integrated function for arcsine, so use the following formula:

2*a(1)-arcsin(1/x)

**Factorial function:**

In a bash shell run the following and substitute 500 with the desired number:

`seq -s "*" 1 500 | bc`