若<img src="https://storage.tutusouti.com/pzst/question_bank/res/ab/3f/ab3f6d384a9cb141a673d9b1c229ec29ce9df50e.jpg?x-oss-process=image/sharpen,200"/>表示与<img src="https://storage.tutusouti.com/pzst/question_bank/res/64/8a/648a8a233227410e57c22263296630f958746d67.jpg?x-oss-process=image/sharpen,200"/><img src="https://storage.tutusouti.com/pzst/question_bank/res/f9/8f/f98f55faed072e3d36ebe49ab3c61633b31a5824.jpg?x-oss-process=image/sharpen,200"/>同方向的单位向量,则下列表示向量<img src="https://storage.tutusouti.com/pzst/question_bank/res/78/7a/787aa48d2f06a271d27eb3b6c72dea3ceef0da6c.jpg?x-oss-process=image/sharpen,200"/>在<img src="https://storage.tutusouti.com/pzst/question_bank/res/f6/5d/f65d426d933a773e212fa19353c099de151e0875.jpg?x-oss-process=image/sharpen,200"/>上的投影向量的是（）。