Question

Sa se calculeze produsul scalar a 2 vectori pentru care a=3, b=9 in situatiile:
Alfa=0 grade
alfa= 30 grade
alfa=60 grade
alfa=90 grade
alfa=45 grade



Exemplu: a x b= ab cos alfa​

Answer 1

Răspuns:

£ = alfa

1) £ = 0°

a × b = ab × cos £

a × b = 3 × 9 × cos 0°

a × b = 27 × 1 = 27

2) £ = 30°

a × b = ab × cos £

a × b = 3 × 9 × cos 30°

a × b = 27 × (radical din 3)/2

3) £ = 60°

a × b = ab × cos £

a × b = 3 × 9 × cos 60°

a × b = 27 × 1/2

a × b = 13,5

4) £ = 90°

a × b = ab × cos £

a × b = 3 × 9 × cos 90°

a × b = 27 × 0 = 0

5) £ = 45°

a × b = ab × cos £

a × b = 3 × 9 × cos 45°

a × b = 27 × (radical din 2)/2