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some kind of chainrule or smthing?

How do i differentiate that one and get the same thing in the brickets sin(y).

Ganesh... maybe i didn't make my self clear that y is a function of t.?? Or is it

me that have misunderstood you? Coud you show me how you diferentiate the

expression?

**GurraTedden**- Replies: 6

Hi guys, I'm stuck again!

And it's mathematical, like always (regret those lazy days back in analytic math courses, haha).

I'm in this situation:

dx=asin(y)dt

(a is a constant value)

where y=y(t)

I want to solve this for x.

smthing like x = smthing + C (constant of integration, or what ever you want to call it)

I can recall it had something to do about, maybe substitution, but i can't see how thats going to happen...

But it's a mechanics problem.

or if I have to find another way of attacking the original problem. I would also like to read it like you did,

but unfortunately I have drawn it correct. The side 0.3 is not the hyp. of the little triangle. I have gone

forth and back on if there is some kind of connection between the ratios, or (what you call the relationship

between the sides that's not the hyp.)

**GurraTedden**- Replies: 5

Hi, check this out:

http://engman.bravehost.com/mechanics/side.JPG

I've been sitting with it for 2 hours now, it just makes me crazy. I mean, it is

a possibility that the mechanical problem that this trig. is derived from is ment

to be solved in an other way, but i wouldn't bet my money on that.

OK! THIS IS ALL SOLVED NOW! No more problems!

**GurraTedden**- Replies: 8

Hi.

How do I solve sin(θ) = 0.38cos(θ) ???

CORRECTION: eq(2) should be: cos(y) - xsin(y)=0!

Of course. I'm just happy that you give it a try.

**GurraTedden**- Replies: 3

This suddenly felt impossible:

How do I transform these three equations...

(1): xz=bc

(2): cos(y) + xsin(y)=0

(3): zsin(y) + xzcos(y) - c(a+b)=0

(three unknown x,y,z with three equations, always solvable right!? But i only want to solve this for x!!!)

(I've looked it through carefully, so it shouldn't be any errors in there)

...to either of these too:

answer, version1: x=1/√((a/b+1)²-1)

, version2: x=tan(arcsin(b/(a+b))

This is how far I've got:

(1) can be rewritten to: x=bc/z , new(4)

(2) -"- : x=cos(y)/sin(y) , new(5)

(3) -"- : z=c(a+b)/(sin(y)+xcos(y)) ,new(6)

(6) in (4) --> x=b(sin(y)+xcos(y))/(a+b) , new(7)

(5) in (7) --> cos(y)/sin(y)=b(sin(y)+cos²(y)/sin(y))/(a+b) --> [multiplying both sides with sin(y)] cos(y)=b/(b+c)

So, finally: I'm getting y=arccos(b/(a+b)), BUT HOW DO I PROCEED... It's a dead end. I don't know what more to do...

Maybe you do?

**GurraTedden**- Replies: 4

Uhum, I was just hoping that there's someone knowing something about

mechanics, or just can flick an eye on my calculations for this problem.

MathIsFun and mathysperson I'm sure will recognize one of these two problems.

http://engman.bravehost.com/mechanics/2probs.JPG

On 7.14 you can have a look of how far I've got, but I'm stuck.

http://engman.bravehost.com/mechanics/incomplete_solution714.JPG

7.39 I haven't a clue how to do it. The answer is: angle between 32.8 and 45 degrees. The 45 degrees

seems logic, and I guess that should calculate the intuition way. I'll buy that.

IF this is the wrong forum, if you wanna strictly do math around here, I would really appreciate a similar

forum with mechanics.

/Mr. G

solution I knew was there. Mathsyperson: I'm impressed! And regarding the "i want this angle

so bad"; It is written by me, and have been more than true for the last 72 hours. But not any more...

hihi... it's like a burden has been lifted from my shoulders, and the salvator:

"www.mathisfun.com". You guys rock!

But, Im convinced that the problem that this algebra subproblem is conected with,

is not ment to be this advanced... so you said that the 1.5m measurement is useless. It seems so

to me to... but it should be involved somehow. So, you are absolute positive that that measurement

cannot unlock an easier solution to this?

under. And the mechanical excercise is now solved, thank

to your algebraic consultancy. A big thanks to you!

Hate having to sit by my self with this kind of lousy problems.

Actually this is a part of a quite simple mechanical problem, and

I'm almost 100 percent sure of that the way they mean, is to be

able to calculate that angle. But, it doesn't seem like that should

be a big problem. I mean, calculating that angle shouldn't be the

head task of the exercise. So, I hope that your answer is not too

advanced, even thought I will appreciate it equally much, my friend!

/Gustav

**GurraTedden**- Replies: 5

Hi, thought that i might just put up all my problems in here, to hope

for the best. Well, i have other problems too, but to get rid of one or

two of them would make my day!

Just check this link out, for the problem:

http://engman.bravehost.com/Jobb/algebra2.JPG

/Gustav

**GurraTedden**- Replies: 19

Hello! I have a problem with an angle. I just cant calculate it.

But I'm pretty sure that this is possible. What do you say!?

I would be more than happy if some of you guys could see how to do this.

The problem is depicted on this adress.

http://engman.bravehost.com/Jobb/algebra.JPG

/Gustav from Sweden

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