Trigonometric functions NEAP questions (1 Viewer)

[BlueGas]

I want to know the answers to all of these questions as I'm not sure if my answers are right, so if you could please answer these questions (doesn't need to have working out), I'll really appreciate it.

 

[leehuan]

a) 4/5 radians
b) (i) 6pi cm^2
b) (ii) (12pi - 9sqrt3) cm^2

Mental arithmetic. See if you agree.

 

[BlueGas]

a) 4/5 radians
b) (i) 6pi cm^2
b) (ii) (12pi - 9sqrt3) cm^2

Mental arithmetic. See if you agree.

Why isn't b) i) 12Pi cm^2? Because the area of a sector is 1/2 x r^2 x theta, right?

So 1/2 x (6)^2 x 2Pi/3 = 18 x 2Pi/3 which equals 12Pi cm^2.

 

[InteGrand]

Why isn't b) i) 12Pi cm^2? Because the area of a sector is 1/2 x r^2 x theta, right?

So 1/2 x (6)^2 x 2Pi/3 = 18 x 2Pi/3 which equals 12Pi cm^2.

Yep, that's right.

 

[leehuan]

Because I looked at the wrong sector. Somehow I interpreted (ii) correctly but (i) wrong.