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Make a plane intersection aa1d1d through the edge BB1 of square abcd-a1b1c1d1, and verify: EF / / BB1
Given that the edge length of cube abcd-a1b1c1d1 is 1, P is the midpoint of Aa1, e is the point on BB1, then the minimum value of PE + EC is ()
A. 2B. 152C. 172D. 3
According to the meaning of the question, we can expand the plane bcc1b1, as shown in the figure, if PE + EC takes the minimum value, then p, e and C are collinear, so the minimum value of PE + EC is PC, because the edge length of cube abcd-a1b1c1d1 is 1, P is the midpoint of Aa1, so | PC | = 172
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