Soal matematika kelas 12 Tolong bantu jawab

proyeksi vektor ortogonal a pada b
[(a · b) / |b|² ] b
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a · b = (1)(5) + (2)(4) + (2)(1)
        = 5 + 8 + 2
        = 15
|b|² = 5² + 4² + 1²
      = 25 + 16 + 1
      = 42

c = [(a · b) / |b|² ] b
c = (15/42) (5, 4, 1)
c = (5/14) (5, 4, 1)