Neural Networks and Deep Learning_week 2_1

Logistic Regression as a Neural Network

1.Binary Classification

** binary classification定义**

其中n为向量的纬度
nations

2.logistic Regression

（逻辑回归是一种学习算法？）

3.logistic Regression Cost Function

cost function反应了参数成本，就是衡量参数w&b在训练集上的效果

Gradient Descent

//梯度下降

一些英语名词：
partial derivative偏导
the slope of the function（函数的斜率），with respect to one of the variables.关于至于

Derivatives

calculus and the derivatives //微积分和导数

More Derivative Examples

computation graph

蓝色的箭头是顺着的

Derivatives with a computation graph

Logistic Regression Gradient Descent

//gradient descent :梯度下降

Gradient Descent on Examples