### 7 September 2016 is a Good BAD

BADs are Basic Arithmetic Dates. The basic BAD is to find an equation using each number in the date only once. All three numbers must be used and the year is a 2-digit year. Note: math functions such as square-root, cube-root, factorial, can be applied to the numbers.

```   9 + 7 = 16
```

The following are 9/7/16 BADs found using various math functions.

```   9 - 7 = sqrt(sqrt(16))
sqrt(9) + sqrt(16) = 7
cuberoot(avg(7, 9)) = sqrt(sqrt(16))
```

One form of BAD is the badPiEval. A badPiEval is when each number of the date is used in an expression that when evaluated approximates Pi (π).

Here the square-root and factorial functions are used to create a badPiEval.

```   (sqrt(9)! + 16) / 7 ~= Pi

* badPiEval:  22/7 approximates Pi rounded to nearest hundredth (3.14)
π ~= 3.1415926535897932384626
```

Another form of BAD is the badAgeEval. A badAgeEval is when each number of the date is used in an expression that when evaluated equals the age of the person (equationeer) finding the badAgeEval.

```   9 * 7 - sqrt(16) = 59

badAgeEval: MathBabbler was 59 years young on 9/7/16.
```

Another form of BAD is the badCardinality. A badCardinality is when each number of the date is used in an expression that when evaluated equals three (i.e. the number of numbers in a date).

```
9 / sqrt(16 - 7) = 3
sqrt(9)! / (16 % 7) = 3

badCardinalityEval: There are three numbers in a date.
```

Another form of BAD is the bad37Eval. A bad37Eval is when each number of the date is used in an expression that when evaluated equals thirty-seven.

```
9 + 7 * sqrt(16) = 37
sqrt(9) * 7 + 16 = 37
sqrt(9)! + 7 + sqrt(16)! = 37

```

Another form of BAD is the bad42Eval. A bad42Eval is when each number of the date is used in an expression that when evaluated equals forty-two.

```
sqrt(9) * 7 * sqrt(sqrt(16)) = 42
7! / sqrt(9 + 16)! = 42

```
##### Exercises
1. `9 + n = 16`

2. `9 + 7 * n = 37`

3. `9 * 7 - n = 59`

4. `(n + 16) / 7 ~= 3.1429` [round to nearest whole number]

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 07 September 2016 