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pythonsqrtmath.sqrt

Displaying sqrt when returning a function


I am just learning to code so i decided to make a project for myself making a function that finds the zero of a parabola. I think the issue i am having is actually printing out the sqrt.

This is the error I receive:

File "C:/Users/someb/AppData/Local/Programs/Python/Python37-32/Quadratic Formula Solver revised.py", line 10, in find_zero
    return float(-b) + "+-" + float(math.sqrt(discriminant)) + "/" + float(2 * a)
TypeError: unsupported operand type(s) for +: 'float' and 'str'

This is my like fifth revision of the code trying different ways, this originally was supposed to display the two different answers.

#Real Zero Finder QUadratic Formula
import math
def find_zero(a,b,c):
    discriminant = (b ** 2 - 4 * a * c)
    if discriminant < 0 :
        return "No real Zeros"
    elif discriminant == 0 :
        return "Vertex is the Zero"
    else:
        #This is where the error is taking place
        return float(-b) + "+-" + float(math.sqrt(discriminant)) + "/" + float(2 * a)

def disc(a,b,c):
    return math.sqrt(b ** 2 - 4 * a * c)

Solution

  • You're getting this error because Python doesn't know how to add a string to a float. You know you're trying to do concatenate the float to the string, but Python doesn't.

    The simplest way to print multiple things in Python 3.6+ is to use formatted string literals (f-strings): https://docs.python.org/3.6/reference/lexical_analysis.html#f-strings You put a f before your string and then put what you want to appear in the string inside curly braces { }.

    return f'{-b} +- {math.sqrt(discriminant)} / {2 * a}'