# Cost function in linear regression

Can anyone help me about cost function in linear regression. As from the below plot we have actual values and predicted values and I assumed the answer as zero but it actually is 14/6?

$$h_\theta$$ implies that you're trying to model the relation between $$h$$ and $$x$$ with an straight line coming from the origin $$(0,0)$$. The parementer $$\theta_1$$ is the slope of this line.
Evaluating $$J(\theta_1=0) = J(0)$$, implies that $$h_\theta(x_i)=0$$ whatever the value of $$x_i$$ is. Since $$m=3$$, and the labels are $$y_1=1, y_2=2, y_3=3$$
$$J(0) = \frac{1}{6}[(0 -1)^2 + (0 - 2)^2 + (0-3)^2] = \frac{14}{6}$$
The value of $$\theta_1$$ for which $$J(\theta_1) = 0$$ is obviously 1
• is y1=1 or y1=0? In the equation you did (0-1)^2? Dec 13 '18 at 6:29