Я пытаюсь создать решатель квадратного уравнения, но он не работает, когда я ввожу коэффициент больше 1? Код и сообщение об ошибке ниже. Любая помощь приветствуется.
print "Welcome to the quadratic equation solver."
print "The general quadratic equation = ax^2 + bx + c.\n"
def POS(a,b):
#This function gives the point at which the quadratic turns
tp = float((-b)/(a*2))
return (tp)
#This allows for the user to input the values of the variables
while True:
s = raw_input ("Please insert a numerical value for a: ")
try:
a = float(s)
break
except ValueError:
print "Please enter a numeric value."
print ("Well done.\n")
while True:
s = raw_input ("Please insert a numerical value for b: ")
try:
b = float(s)
break
except ValueError:
print "Please enter a numeric value."
print ("Well done.\n")
while True:
s = raw_input ("Please insert a numerical value for c: ")
try:
c = float(s)
break
except ValueError:
print "Please enter a numeric value."
print ("Well done.\n")
#This uses the function to give the co-ordinate of the turning point
print POS(a,b), "is the x-value of the turning point"
print ((a)*(POS(a,b)**2))+((b)*POS(a,b))+c, "is they y-value of the turning point. \n"
#This tells whether the quadratic is positive or negative
if a >0:
print "The quadratic is positive.\n"
if a<0:
print "The quadratic is negative.\n"
#This determines the root of the quadratic
root1 = (-b +((b**2) - (4*a*c))**0.5) / (2 * a)
root2 = (-b -((b**2) - (4*a*c))**0.5) / (2 * a)
print "The quadratic has a root at x =",root1
if root1 != root2:
print "The quadratic has another root at x =",
#This uses the discriminant to determine the nature of the quadratic
if (b**2)-(4*a*c) == 0:
print root1
elif (b**2)-(4*a*c) > 0:
print root1 and root2
elif (b**2)-(4*a*c) < 0:
print "The quadratic contains no roots"
for x in range(-1000,1000):
quadratic = (a*x**2)+(b*x)+c
#Determines the derivitive and second derivitive of the quadratic
print "The derivitive of the quadratic is: ",2*a,"x", "+",b
print "The second derivitive of the quadratic is"
#Create plot
X = arange (-1000,1000,1)
plot(X, quadratic, linewidth=3, label="quadratic")
#Create title and axes label
title ("Graph of the quadratic")
xlabel ("x")
ylabel ("y")
#grid
grid(True)
legend()
show()
Сообщение об ошибке:
Traceback (most recent call last):
File "C:\Users\Peter\Downloads\test.py", line 49, in <module>
root1 = (-b +((b**2) - (4*a*c))**0.5) / (2 * a)
ValueError: negative number cannot be raised to a fractional power
(b**2) - (4*a*c)
отрицательный. - person Peter Wood   schedule 17.05.2015if (b**2)-(4*a*c) > 0
перед вычислением корней? - person Julien Spronck   schedule 17.05.2015b**2 - 4*a*c
может привести к очень маленькому отрицательному числу, когда оно должно быть равно нулю. Это не значит, что уравнение не имеет корней. - person TigerhawkT3   schedule 17.05.2015cmath.sqrt
для получения сложного корня. - person Peter Wood   schedule 21.05.2015