分解因式:
=___________________________.
若点P(,![]()
)在![]()
轴上,则它关于![]()
轴的对称点的坐标是___________________.![]()
已知三角形的三边长分别为3,8,,若![]()
为偶数,则![]()
=_____________________.![]()
如图,△ABC中,∠C=90°,AD平分∠BAC,AD=4,CD=2,AC=2
,则△ABD的面积是_______________.

=__________________________________.
已知
=4,
=3,则
=_______________________.
