HALOOO MOHON BANTUUU
Penjelasan dengan langkah-langkah:
PQ = A = (6-5, 2-3, -4+4) = (1, -1, 0)
PR = B = (5-5, 4-3, -4+4) = (0, 1, 0)
A.B = (1.0 + 1.-1 + 0.0)
A.B = – 1
|A| = √(1² + (-1)² + 0²) = √2
|B| = √(0² + 1² + 0²) = √1 = 1
kosinus sudut antara PQ dan PR adalah cos ∅
A.B –1 1
cos ∅ = -------- = --------- = – ----
|A||B| √2.1 √2
cos ∅ = – ½√2
∅ = arc.Cos (–½√2)
∅ = 135°
[answer.2.content]
