I am having trouble understanding the difference between Q21 in exam 2020 and Q21 in 2019. From my understanding, the "derivative-free random search discussed in class" (Q21 exam 2019) and the "random search discussed in class [...] using random directions with line-search" (Q21 exam 2020) are equivalent.

The only difference that I notice is the fact that in the 2020 exam the "line search on random directions" is explicitly stated. However, based on slide 10 of lecture 10, the "random search algorithm" is defined as an algorithm that use line search to minimize along a randomly selected direction. From my understanding, it would make the statement in the 2020 exam "redundant" rather than the one in the 2019 incomplete.

## Q21 exam 2019 and Q21 exam 2020

Hi,

I am having trouble understanding the difference between Q21 in exam 2020 and Q21 in 2019. From my understanding, the "derivative-free random search discussed in class" (Q21 exam 2019) and the "random search discussed in class [...] using random directions with line-search" (Q21 exam 2020) are equivalent.

The only difference that I notice is the fact that in the 2020 exam the "line search on random directions" is explicitly stated. However, based on slide 10 of lecture 10, the "random search algorithm" is defined as an algorithm that use line search to minimize along a randomly selected direction. From my understanding, it would make the statement in the 2020 exam "redundant" rather than the one in the 2019 incomplete.

Am I missing something ?

Thanks for your help.

To my understanding, the big difference of exam 2019 is that the step size is optimal line search rather than 1/L.

Ah yes. I did not notice the step size detail. You're probably right, thanks.

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