2U Trig (1 Viewer)

[Speed6]

Question 14 from Cambridge Exercise 5B.

 

[InteGrand]

Question 14 from Cambridge Exercise 5B.

That missing angle ZXN is just 30º, since the full circle would be 360º, and you've already drawn 330º of it. (I'm using N to refer to a point on that dotted arrow (N for North, since that arrow is pointing North).)

 

[Speed6]

That missing angle ZXN is just 30º, since the full circle would be 360º, and you've already drawn 330º of it. (I'm using N to refer to a point on that dotted arrow (N for North, since that arrow is pointing North).)

Ok so what do you mean? How can I work out ZXY?

 

[InteGrand]

Ok so what do you mean? How can I work out ZXY?

That missing angle is just 30º, and angle ZXY is just the sum of that missing angle and the 60º angle you've drawn (since the missing angle and the 60º angle are adjacent angles).

 

[Speed6]

That missing angle is just 30º, and angle ZXY is just the sum of that missing angle and the 60º angle you've drawn (since the missing angle and the 60º angle are adjacent angles).

Oh ok, makes much more sense now.

So I just do 360-330 to get 30°.

...and now I add 60+30=90°.

Thanks.

So when the question asks me show, mathematical working out is affordable right? As I do not have to prove anything or justify my calculation with a few words?!

 

[leehuan]

ZXN = 360 - 330 = 30 (angles at a point)

Therefore ZXY = 30 + 60 = 90

There, that's it.

(With degree symbols everywhere of course.)

 

[Speed6]

why the eff did I say affordable? I wasn't meant to say that lmao!

 

[InteGrand]

Oh ok, makes much more sense now.

So I just do 360-330 to get 30°.

...and now I add 60+30=90°.

Thanks.

So when the question asks me show, mathematical working out is affordable right? As I do not have to prove anything or justify my calculation with a few words?!

This Q would probably just be worth 1 mark since it doesn't require lengthly calculations or derivations, but since it's a 'show', you'd have to provide some reason/s of course. So a justification to give would be like angle ZXN = 360º – 330º (angle of revolution is 360º (aka angles at a point sum to 360º)) = 30º.

(And then angle ZXY = 30º + 60º (adjacent angles) = 90º.)

Edit: done above