Question 2: rewrite tan 2013x = tan (2014x-x) tan 2015x = tan (2014x+x) and divide it into tan 2014x * a *.

Where A>0 so the result is that the zero number of tan20 14x in [0, π] is the demand.

Question 3: Let A be a symmetrical point A 1 (1 2) about y=x and a symmetrical point A2 about x axis, connect A 1A2, and pass through y=x and x axis respectively.

At c and b, the perimeter p is the smallest, and P=A 1A2= root number 10.

Question 4: P2k+ 1P2k=2*2k, so the answer is 4048.

The fifth body: given the length of three sides of the tetrahedron vertex and the included angle between the three sides, there is an area formula (with determinant) _

Directly bring in the available V= root number 10/3.

Question 6: Do it in the exponential form of complex numbers. I only think of this slightly cumbersome method.

Final result [√(2-√3), √(2+√3)]