Question: In this problem, we will show that the convergence rate for optimizing smooth convex functions can be recovered (up to a logarithmic factor) by the

 In this problem, we will show that the convergence rate for

In this problem, we will show that the convergence rate for optimizing smooth convex functions can be recovered (up to a logarithmic factor) by the convergence rate for optimizing smooth and strongly convex functions. Suppose that we have an algorithm A (which is not necessarily gradient descent). This algorithm takes an initial point x0 E Rd and an iteration number t E N as input, and has the following guarantee: for any B-smooth and a-strongly convex function g : Rd -> R, after computing the gradient of g at t points, the output at satisfies: g(xt) - g(x) R be a convex and B-smooth function, and let x* E argminTERd f(x). (1) [2 points] Let g(x) = f(x)+ , lx - coll2 (a > 0) and x E argminceRag(x). Prove |la - xol|2 (2) [4 points] Prove that for any initial point ro E Rd and iteration number t E N, we can use the algorithm A to find a point at such that f(xt) - f(a*)

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