Question

因此对于我的程序，我正在解决一个基于用户输入的二次方程。因此，在我的代码中，我想做到的是，当用户为a或b输入1或-1时，而不是写-1x 2 + 1x时，它应该是-x 2 + 1。但是，当我输入-1并为a和b输入-1时，程序将跳过显示该函数的过程，就像使用其他任何值一样。但是，与其他任何值一样，在尝试使用compute_discriminant函数来解决判别式时，我在代码的第48行指出一条错误：第48行，compute_discriminate x1 =（-b + math.sqrt（d））/（2 * a） ValueError：数学域错误

尽管a和b分别为-1和-1，该程序在解决判别式上没有问题。

a = 0
b = 0
c = 0
import math

def evaluate_quad_function(a, b, c, x):
    f_of_x = a*(x**2) + (b * x) + c
    return f_of_x  # return the calculated result
print("Welcome to the Quadratic Solver for f(x)=ax^2+bx+c")
a = input("Enter Value for a:")
b = input("Enter Value for b:")
c = input("Enter Value for c:")
# cannot do math on string, convert to float
a = float(a)
b = float(b)
c = float(c)
f_x0= a*((-b)/(2*a)**2) + (b * (-b)/(2*a)) + c

def print_sign(x):
    # check the sign if positive or negative
    return '+' if x > 0 else '-'
if a == 1:
        print("\nFunction is: f(x)= ", "x**2 ", print_sign(b), abs(b), "x ", print_sign(c), abs(c), sep="")
elif b == 1:
        print("\nFunction is: f(x)= ",a, "x**2 ", print_sign(b), "x ", print_sign(c), abs(c), sep="")
elif c == 1:
        print("\nFunction is: f(x)= ",a, "x**2 ", print_sign(b), abs(b), "x ", print_sign(c), abs(c), sep="")

x = input("Enter Value for x:")
x = float(x)


fx = evaluate_quad_function(a, b, c, x)
print("F"+"("+str(x)+")""=", str(fx))
temp = input("\nPress Enter to continue...")  # wait

x0 = -b/(2*a)
x0 = float(x0)
if a>0:
    print("f(x) has a minimum at "+ str(x0)+" with a value f(x0)="+ str(f_x0))
else:
    print("f(x) has a maximum at " + str(x0) + " with a value f(x0)=" + str(f_x0))
temp = input("\nPress Enter to continue...")  # wait

def compute_discriminate():
    print("Solving for f(x) = 0")
    d = (b**2) - (4*a*c)
    x1 = (-b + math.sqrt(d))/(2*a)
    x2 = (-b - math.sqrt(d))/(2*a)
    print("Discriminant is", str(d))
    if d > 0:
        (print("Two Real Solutions",str(x1), "and", str(x2) ))

    if d == 0:
        print("One real solution:", str(x0))

    if d < 0:
        print("No real solution.")


print(compute_discriminate())

第48行，在compute_discriminate x1 =（-b + math.sqrt（d））/（2 * a）中 ValueError：数学域错误

预期结果是求解并返回判别函数及其值。

数学域错误和语句打印两次

0 个答案: