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Assume that your hypothesis function for linear regression is of the form f(x) = w0 + w1x and that the current values of w0 and w1 are 1 and 2 respectively. Further assume that you are using a learning rate (alpha) of 0.001What is the new w0 value associated with the point (1, 12), after one gradient update?

Question

Assume that your hypothesis function for linear regression is of the form f(x) = w0 + w1x and that the current values of w0 and w1 are 1 and 2 respectively. Further assume that you are using a learning rate (alpha) of 0.001What is the new w0 value associated with the point (1, 12), after one gradient update?

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Solution

In order to update the parameters w0 and w1, we need to compute the gradient of the cost function. For a simple linear regression, the cost function is the mean squared error (MSE) and its gradient with respect to w0 is given by:

∂/∂w0 = 2/N * Σ(f(xi) - yi)

where N is the number of observations, xi are the input features, yi are the target values, and f(xi) is the prediction of the model.

Given that we only have one point (1, 12), N=1, xi=1, and yi=12. The current prediction of the model is f(1) = w0 + w11 = 1 + 21 = 3.

Therefore, the gradient of the cost function with respect to w0 is:

∂/∂w0 = 2/1 * (3 - 12) = -18

The update rule for gradient descent is:

w0_new = w0_old - alpha * ∂/∂w0

Substituting the given learning rate alpha=0.001 and the computed gradient, we get:

w0_new = 1 - 0.001 * -18 = 1.018

So, the new value for w0 after one gradient update for the point (1, 12) is 1.018.

This problem has been solved

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