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C2 Trig

6tanx=1 0_<x_<180

tan^-1(1/6) = 9.5 189.6 in the book im wrong could someone tell me why ?
Reply 1
Avatar for 0range
0range
20
Do you know what a cast diagram is? and are you in Degrees mode

EDIT: Just checked myself you should get 9.5 on its own as 189.6 is outside the range.
(edited 12 years ago)
Reply 2
Avatar for ch0wm4n
ch0wm4n
10
Original post by Ganhad
6tanx=1 0_<x_<180

tan^-1(1/6) = 9.5 189.6 in the book im wrong could someone tell me why ?


Range is 0 < x < 180.

Spoiler

.
Reply 3
Avatar for Ganhad
Ganhad
OP
2
Why ? the cast diagram it looks as if im supposed to add the the tan is positive?
Reply 4
Avatar for TenOfThem
TenOfThem
18
9.5 is the only answer
Reply 5
Avatar for ch0wm4n
ch0wm4n
10
Original post by Ganhad
Why ? the cast diagram it looks as if im supposed to add the the tan is positive?


The number should lie between the range, when you inverse 1/6 you get 9.5 which lies between 0 < x < 180. :smile:
Reply 6
Avatar for Ganhad
Ganhad
OP
2
im confused so 9.5 is the only value?
Reply 7
Avatar for ch0wm4n
ch0wm4n
10
Original post by Ganhad
im confused so 9.5 is the only value?


Yes as it is the only possible value in the range 0 < x< 180.
Reply 8
Avatar for Ganhad
Ganhad
OP
2
Original post by ch0wm4n
Yes as it is the only possible value in the range 0 < x< 180.


could you show me how to do this one untitled.bmp sorry for the poor during i have to find theta x and the radius if someone gives me the first step i can work from there
Reply 9
Avatar for raheem94
raheem94
13
Original post by Ganhad
could you show me how to do this one untitled.bmp sorry for the poor during i have to find theta x and the radius if someone gives me the first step i can work from there


See the image below:




We need to find the side 'x', use the cosine rule to find it.

The angle θ \theta can be found by using the sine rule.

If you still can't do it, then see the spoiler.

Spoiler

Reply 10
Avatar for Ganhad
Ganhad
OP
2
how would you know which values to use for the cosine rule when there are 3 values stated
Reply 11
Avatar for raheem94
raheem94
13
Original post by Ganhad
how would you know which values to use for the cosine rule when there are 3 values stated


Do you know how to use the cosine rule?

Have you seen the spoiler in my post?

The values we have to use are obvious from the diagram, we need to take 12 at the LHS and other at the RHS.

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