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# C2 Trig watch

1. If tan theta = 1 and theta is acute, find the exact values of:
sin theta/cos theta.

I understand that I need to make a right angled triangle with opp =1/adj = 1 and hyp = root 2. But what does the question imply by stating that the angle is acute? If another question says the angle is obtuse what does it mean? I know that theta would be in the range 0 < x < 90 and 90 < x < 180.

Has it got to do with which angle to use when drawing the triangle?
2. tan(45)=1
tan(225)=1

Which one do you want?
3. (Original post by BabyMaths)
tan(45)=1
tan(225)=1

Which one do you want?
ohh haha, i was overthinking this. cheers

If sin theta is 5/13, and theta is obtuse, find the exact values of cos theta/tan theta.

I got theta = 22.6 and the other value is 157.4 . But how can I make a right angled triangle with an angle of 157.4?
4. (Original post by UKBrah)
ohh haha, i was overthinking this. cheers

If sin theta is 5/13, and theta is obtuse, find the exact values of cos theta/tan theta.

I got theta = 22.6 and the other value is 157.4 . But how can I make a right angled triangle with an angle of 157.4?
The first diagram here might help.
5. together with this

6. (Original post by BabyMaths)
together with this

I get cos x = 12/13 and tan x = 5/12.
The answers are negative tho, is this because both x co-ordinates are negative in the quadrant in which the triangle is in?
Attached Images

7. (Original post by UKBrah)
I get cos x = 12/13 and tan x = 5/12.
The answers are negative tho, is this because both x co-ordinates are negative in the quadrant in which the triangle is in?
You should have -12 rather than 12 in the diagram and then you have

tan (157.38..)= 5/-12= - 5/12

and

cos(157.38..)= -12/13.

8. (Original post by BabyMaths)
You should have -12 rather than 12 in the diagram negative and then you have

tan (157.38..)= 5/-12= - 5/12

and

cos(157.38..)= -12/13.

how can distance be negative?
9. (Original post by UKBrah)
how can distance be negative?
distance isn't but direction can be

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