9.已知,,则 ▲ .
10.在等腰三角形中,底边, , , 若, 则 ▲ .
11.已知,若过轴上的一点可以作一直线与相交于两点,且满足,则的取值范围为 ▲ .
12.如图,在三棱锥中, 、、两两垂直,且.设是底面内一点,定义,其中、、分别是三棱锥、 三棱锥、三棱锥的体积.若,且恒成立,则正实数的最小值为 ▲ .
13.已知的三边长成等差数列,且则实数的取值范围是 ▲ .
14.已知函数,若给定非零实数,对于任意实数,总存在非零常数,使得恒成立,则称函数是上的级类周期函数,若函数是上的2级2类周期函数,且当时,,又函数.若,使成立,则实数的取值范围是 ▲ .
二、解答题:本大题共6小题,共90分.解答时应写出必要的文字说明、证明过程或演算步骤.
15.(本小题满分14分)
在如图所示的ut..................演XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX平面直角坐标系中,已知点XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX和点,,且,其中为坐标原点.