Given vector u = 30 ⟨cos 60°, sin 60°⟩, what are the magnitude and direction of −6u?

A.
210; 60°

B.
210; 240°

C.
180; 240°

D.
-180; 60°

Question

Given vector u = 30 ⟨cos 60°, sin 60°⟩, what are the magnitude and direction of −6u?

A.
210; 60°

B.
210; 240°

C.
180; 240°

D.
-180; 60°

OLIVER69 · Answer

Your answer is D because 60 + 60 = 120 then add 30 to 120, which equals 180, then you know it has to be 60 degrees because cos60+sin60, which you can solve on a calculator. Makes sense?

kekeman · Answer

@oliver69 wrote:

Your answer is D because 60 + 60 = 120 then add 30 to 120, which equals 180, then you know it has to be 60 degrees because cos60+sin60, which you can solve on a calculator. Makes sense?

Okay so it would be -180; 60°?

OLIVER69 · Answer

@kekeman wrote:

@oliver69 wrote:

Your answer is D because 60 + 60 = 120 then add 30 to 120, which equals 180, then you know it has to be 60 degrees because cos60+sin60, which you can solve on a calculator. Makes sense?

Okay so it would be -180; 60°?

yes I do believe it would be

kekeman · Answer

Thank you

Narad · Answer

\ $$-6u=180\left( \frac{- 1 }{ 2 },\frac{- \sqrt{3} }{ 2 } \right)$$ $$\left| -6u \right|=180$$ $$\theta=180+60=240$$

kekeman · Answer

Ahhhhhhhhhhhhhhhhhhhhh I got it wrong damn it