23: The type is ∞⋅0. Here is is not immediately clear what is the better choice for "putting under". In both options we get a complicated composed function in the denominator, so there is no difference there. Thus it may help to look at the numerator. If we leave the tangent there, then after differentiating it we get cosine to power negative two, which is troublesome at point 1. On the other hand, if we leave the logarithm in the numerator, derivative will turn it into 1/x, which is nice at 1. Thus the better choice is to "put under" the tangent.

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