Hello,

I was having problem understanding how this system of equation is singular.

a=1

b=2

a+b =3

we can find that it has a unique solution and is thus it is not singular.

Previously in the lecture it was mentioned that singular would mean no unique solution.

link to lecture : https://www.coursera.org/learn/machine-learning-linear-algebra/lecture/e5jZi/linear-dependence-and-independence

time stamp - 3:44

Thanks for helping

TMosh
2
It’s singular because it’s really only two independent equations, and the 3rd line is the linear combination of the first two.

It isn’t three separate equations. There is no ‘c’ at all, because its weight is always 0.

I see, so in the context of 3 variables it is singular. However if we considered only 2 variables it would have been non singular.

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Right. It’s worth mentioning the next level of detail on that point. There are two ways you can satisfy the condition “no unique solution”:

- No solution at all
- An infinite number of solutions

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Understood, thank you for helping with the issues @TMosh @paulinpaloalto

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