Exam Professional Data Engineer topic 1 question 63 discussion

For fitting a linear classifier when the data is in a circle use A.

Answer: A

I think A should be x^2+y^2. We need a circle to classify the data.

Just a note, they are using X2 and Y2 to mean Xsquared, and Ysquared. This is a circle in the form X2+Y2 = k, so for a given k will split that dataset nicely.

It's not obvious to me it is A. As others said, cos(X) does ignore the Y value. But answer A does not seem good either. The differences seem minimal. If you do A then you have the following issues. If you take elements in the bottom right or the top left of the circle, they will all have the same value, ZERO. Not only that, they will actually have the same value with the elements in the middle of the circle which are completely black. Moreover, elements on the extreme right and extreme right will have different values (-x_max and +x_max). However, if you use a cos(x) then the elements in the beginning

A. X2+Y2 The synthetic feature that should be added in this case is the squared value of the distance from the origin (0,0). This is equivalent to X2+Y2. By adding this feature, the classifier will be able to make more accurate predictions by taking into account the distance of each data point from the origin. X2 and Y2 alone will not give enough information to classify the data because they do not take into account the relationship between X and Y. D. cos(X) is not a suitable option because it does not take into account the Y coordinate.

A is the correct answer as graph of circle is x^2 + y^2

Answer is A: The answer reflects 'x' to the 2nd power + 'y' the 2nd power. I guess they can't use carots in the exam answers!

A is right Reference: https://medium.com/@sachinkun21/using-a-linear-model-to-deal-with-nonlinear-dataset-c6ed0f7f3f51

https://developers.google.com/machine-learning/crash-course/feature-crosses/video-lecture

linear circle X2+Y2 https://www.stat.cmu.edu/~cshalizi/dm/20/lectures/08/lecture-08.html

If the shape was a circle, it would be (x^2 + y ^2). But I think that a quadric curve will do a better job of separating the two classes, so it would be (x^2)

Answer: A. X^2+Y^2 is the equation of a circle.

C'est A

only A is draw a circle

Equation of circle as represented in the question

F(x) as A B C will have always a positive values as result, for A will need a third dimenssion Z to represent data, only D:cos(x) can be presented as the shown classification. this is a math question