Question

ΔV²=V²a+V²b - 2Va.Vb cos 0 ΔV²=(60)²+(80)²-2.60.80 cos 60°? heeelllpppp :)

Answer 1

ΔV²=(60)²+(80)²-2.60.80 cos 60°
ΔV²=3600+6400-2.60.80.0,5
ΔV²=10000-4800
ΔV²=5200
ΔV=+/-√5200=+/-20√13

Answer 2

Δv² = (60)² + (80)² - 2.60.80.cos 60º

Δv² = 3600 + 6400 - 9600.0,5

Δv² = 10000 - 4800

Δv² = 5200

5200 | 2
2600 | 2
1300 | 2
0650 | 2
0325 | 5
0065 | 5
0013 | 13
0001

5200 = 2².2².5².13

√Δv² = √5200

Δv = √2².2².5².13

Δv = 2.2.5.√13

Δv = ± 20√13

Espero ter ajudado.