The sigmoid function is defined as sigmoid(x) = 1/(1+e-x). If the score is defined by 4x1 + 5x2 - 9 = score, then which of the following points has exactly a 50% probability of being blue or red? (Choose all that are correct.)
answers: (1,1) - (2,4) - (5,-5), (-4,5)
can someone explains how to solve this question?
Im taking the same udacity course. You asked the wrong question, got the wrong answer. its 1/1(1+e^-x)
the correct code is
from math import e,pow
#Equation: 4x1+5x2-9=score
#weights are 4,5 and bias is -9, find the sigmoid(x) = 1/(1+e-x).
features=[(1,1),(2,4),(5,-5),(-4,5)]
def linear_func(features):
for x in features:
score= 4*x[0]+ 5*x[1]-9
y = 1 / (1 + pow(e,- score))
print("X",x,score,y)
#call the function
linear_func(features)
answer is 1,1 and -4,5
answer on udacity: That's correct. Intuitively, if you look at the plot for a sigmoid function, the probability would always be 50% if the score evaluates to zero.