在\(∆ABC \)中,\(\left| \overrightarrow{AB}+ \overrightarrow{AC}\right|=\left| \overrightarrow{AB}- \overrightarrow{AC}\right| \),\(AB=4\),\(AC=3\),则\(\overrightarrow{BC} \)在\(\overrightarrow{CA} \)方向上的投影是\((\) \()\)
进入组卷