Cara menggunakan python math square root

Square Roots in Mathematics

In algebra, a square, x, is the result of a number, n, multiplied by itself: x = n²

You can calculate squares using Python:

>>>

>>> n = 5
>>> x = n ** 2
>>> x
25

The Python

>>> 1 ** 2
1

>>> 2 ** 2
4

>>> 3 ** 2
9

The square root, then, is the number n, which when multiplied by itself yields the square, x.

In this example, n, the square root, is 5.

25 is an example of a perfect square. Perfect squares are the squares of integer values:

>>>

>>> 1 ** 2
1

>>> 2 ** 2
4

>>> 3 ** 2
9

You might have memorized some of these perfect squares when you learned your multiplication tables in an elementary algebra class.

If you’re given a small perfect square, it may be straightforward enough to calculate or memorize its square root. But for most other squares, this calculation can get a bit more tedious. Often, an estimation is good enough when you don’t have a calculator.

Fortunately, as a Python developer, you do have a calculator, namely the !

The Python Square Root Function

Python’s

>>> 1 ** 2
1

>>> 2 ** 2
4

>>> 3 ** 2
9

>>> 1 ** 2
1

>>> 2 ** 2
4

>>> 3 ** 2
9

>>> 1 ** 2
1

>>> 2 ** 2
4

>>> 3 ** 2
9

You’ll begin by importing

>>> 1 ** 2
1

>>> 2 ** 2
4

>>> 3 ** 2
9

>>>

>>> import math

That’s all it takes! You can now use

>>> 1 ** 2
1

>>> 2 ** 2
4

>>> 3 ** 2
9

sqrt() has a straightforward interface.

It takes one parameter,

>>> import math

>>> import math

The return value of sqrt() is the square root of

>>> import math

>>> import math

Let’s take a look at some examples of how to (and how not to) use sqrt().

>>> import math

>>> math.sqrt(49)
7.0

>>> math.sqrt(49)
7.0

>>> import math

>>> import math

>>> math.sqrt(70.5)
8.396427811873332

>>> 8.396427811873332 ** 2
70.5

>>> math.sqrt(49)
7.0

>>> math.sqrt(0)
0.0

>>> math.sqrt(-25)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: math domain error

>>> math.sqrt(49)
7.0

Square Roots in the Real World

To see a real-world application of the Python square root function, let’s turn to the sport of tennis.

Imagine that Rafael Nadal, one of the fastest players in the world, has just hit a forehand from the back corner, where the baseline meets the sideline of the tennis court:

Now, assume his opponent has countered with a drop shot (one that would place the ball short with little forward momentum) to the opposite corner, where the other sideline meets the net:

How far must Nadal run to reach the ball?

You can determine from that the baseline is 27 feet long, and the sideline (on one side of the net) is 39 feet long. So, essentially, this boils down to solving for the hypotenuse of a right triangle:

Using a valuable equation from geometry, the Pythagorean theorem, we know that a² + b² = c², where a and b are the legs of the right triangle and c is the hypotenuse.

Therefore, we can calculate the distance Nadal must run by rearranging the equation to solve for c:

You can solve this equation using the Python square root function:

>>>

>>> a = 27
>>> b = 39
>>> math.sqrt(a ** 2 + b ** 2)
47.43416490252569

So, Nadal must run about 47.4 feet (14.5 meters) in order to reach the ball and save the point.

Conclusion

Congratulations! You now know all about the Python square root function.

You’ve covered:

• A brief introduction to square roots
• The ins and outs of the Python square root function, sqrt()
• A practical application of sqrt() using a real-world example

Knowing how to use sqrt() is only half the battle. Understanding when to use it is the other. Now, you know both, so go and apply your newfound mastery of the Python square root function!