Help peter not fail methods thread :P

[pete_owntbychem]

Hey Im just making a new thread (bit like becs) for methods help..... Im pretty noobish at methods

thanks


Questions so far

Use a calculator to covert the following angles from radians to degrees

(a) 0.6
(b) 5.18
(c) 6.00

(this seems a really easy question but there are no examples in the book so I have no clue what to do)

thats all for now

[Mao]

if you know how to work ratios, it is just trivial =)

[pete_owntbychem]

if you know how to work ratios, it is just trivial =)

so for example ... with (a) is this what you mean

3.14(pi):180
as 0.6: x

and we just have to find x???

[mark_alec]

(radians) * 180 / pi = (degrees)

[Odette]

(radians) * 180 / pi = (degrees)

Yes do that lolz =)

[Mao]

if you know how to work ratios, it is just trivial =)

so for example ... with (a) is this what you mean

3.14(pi):180
as 0.6: x

and we just have to find x???

yep, precisely that.


if you want to express this process in a single line formula, mark_alec has already done so.

[pete_owntbychem]

thanks a lot....... it seems so easy now lol
i think i was confused cause I didn't know the 0.6 was a radian (i thought it was a random number which we had to convert to a radian then convert into degrees)....

I thought this ...because in the previous question, radions were like:
2pi/3

and then i saw a radian as 0.6, so I didn't know it was already a radian
(sorry if I've confused you with my weird explanation)

thanks for the help...

[pete_owntbychem]

some more nooby q's (sorry, if im offending all maths genius's in this thread by asking help for really easy q's)

For each of the following angles, t, determine the values of sin t and cos t

(A) t = 0
(B) t = 3pi/2
(C) t = -3pi/2
(D) t = 5pi/2

PS: The reason I don't know these q's is cause I am trying to get ahead of the class =) =) In term 1 I fell behind, I had a lot of trouble picking myself up and catching up the class, Im trying not to let that happen again

[Mao]

remember your unit circle, your quadrants, your exact values, the symmetry. [long story short read over that section in your textbook again]

and, also remember that 2pi is a whole circle, so taking away 2pi does not change the result

[/0]

some more nooby q's (sorry, if im offending all maths genius's in this thread by asking help for really easy q's)

For each of the following angles, t, determine the values of sin t and cos t

(A) t = 0
(B) t = 3pi/2
(C) t = -3pi/2
(D) t = 5pi/2

PS: The reason I don't know these q's is cause I am trying to get ahead of the class =) =) In term 1 I fell behind, I had a lot of trouble picking myself up and catching up the class, Im trying not to let that happen again

There is an easy way to remember the exact values:











See the pattern? 

And if you need the exact value of , just remember that , and you have all your exact values!

[Mao]

use your symmetry.

its all there in the unit circle, just need to recognise it.

[Glockmeister]

thanks a lot....... it seems so easy now lol
i think i was confused cause I didn't know the 0.6 was a radian (i thought it was a random number which we had to convert to a radian then convert into degrees)....

I thought this ...because in the previous question, radions were like:
2pi/3

and then i saw a radian as 0.6, so I didn't know it was already a radian
(sorry if I've confused you with my weird explanation)

thanks for the help...

Like degrees, radians have a unit (although in maths, its usually omitted). You can assume that if you don't see a symbol next to a number (and your doing something related to trig), that it is radians, not degrees

[mark_alec]

Like degrees, radians have a unit (although in maths, its usually omitted).

They are actually a dimensionless quantity, since a radian is defined as arclength / radius.

[Glockmeister]

yeah.. opps

[pete_owntbychem]

Some new questions

Find the general solution for ...

2cos(3x) +1 = 0


Also
Find the general solution for: