Math Help Forum - Trigonometry http://www.mathhelpforum.com/math-help Graphing trig expressions, identities, angles, applied questions en Fri, 20 Nov 2009 22:05:09 GMT vBulletin 60 http://www.mathhelpforum.com/math-help/images/MHF/misc/rss.jpg Math Help Forum - Trigonometry http://www.mathhelpforum.com/math-help Weight of a crate and tension of a rope http://www.mathhelpforum.com/math-help/trigonometry/115804-weight-crate-tension-rope.html Fri, 20 Nov 2009 22:04:17 GMT Okay...so, these are my example problems for this section. Section Level Video: Section 7.5 (http://media.pearsoncmg.com/aw/aw_lial_trigonomet_9/video/llt09_slv_7_5.html#) This is literally the same series of problems I have in my book. I have no other material teaching me in this section. And... Okay...so, these are my example problems for this section. Section Level Video: Section 7.5 This is literally the same series of problems I have in my book. I have no other material teaching me in this section.

And here's the problem I have from this section:

"A crate is supported by two ropes. Rope 1 makes an angle of 46 degrees 23 minutes with the horizontal and has a tension of 98.4 pounds on it. Rope 2 is horizontal. Find the weight of the crate and the tension in the horizontal rope."

From what I can tell, this is not an application of the law of sines or cosines. How do I solve this? ]]> Trigonometry Wolvenmoon http://www.mathhelpforum.com/math-help/trigonometry/115804-weight-crate-tension-rope.html <![CDATA[Can't solve this!!!]]> http://www.mathhelpforum.com/math-help/trigonometry/115783-cant-solve.html Fri, 20 Nov 2009 20:37:28 GMT Attachment 13941 (http://www.mathhelpforum.com/math-help/attachments/trigonometry/13941-cant-solve-20.11.png) Attachment 13941
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]]> Trigonometry livmed http://www.mathhelpforum.com/math-help/trigonometry/115783-cant-solve.html <![CDATA[Trigonometric Word Problem involving Law of Sines & Law of Cosines; I am so clueless.]]> http://www.mathhelpforum.com/math-help/trigonometry/115737-trigonometric-word-problem-involving-law-sines-law-cosines-i-am-so-clueless.html Fri, 20 Nov 2009 14:29:33 GMT Hi there, I just heard about this website from a math tutor after she couldn't help me figure out these problems herself! Hopefully someone here from around the world could help me with these two problems...

1. A rocket tracking station has two telescopes A and B, placed 1.4 miles apart. The telescopes lock onto a rocket and transmit their angles of elevation to a computer after a rocket launch. What is the distance to the rocket from telescope B at the moment when both tracking stations are directly east of the rocket telescope A reports an angle of elevation of 29 degrees and telescope B reports an angle of elevation of 49 degrees?

I keep doing this problem over and over, and keep getting the wrong answer, my only resolution would be that maybe I'm setting the problem up wrong..?


2. A famous golfer tees off on a straight 380 yard par 4 and slices his drive to the right. The drive goes 280 yards from the tee. Using a 7-iron on his second shot, he hits the ball 160 yards and it lands inches from the hole. How many degrees (to the nearest degree) to the right of the line from the tee to the hole, did he slice his drive?

For this one I don't even know where to start...(Worried)

If anyone would take the time to try and solve any of these it would be tremendously appreciated! ]]> Trigonometry mdebourg http://www.mathhelpforum.com/math-help/trigonometry/115737-trigonometric-word-problem-involving-law-sines-law-cosines-i-am-so-clueless.html solve trig equation help. http://www.mathhelpforum.com/math-help/trigonometry/115733-solve-trig-equation-help.html Fri, 20 Nov 2009 13:01:48 GMT Solve, in the interval 0° ≤ θ<360°, the following equations. Give answers to the nearest 0.1°.

sin \theta + cos \theta = 1 ]]> Trigonometry Tweety http://www.mathhelpforum.com/math-help/trigonometry/115733-solve-trig-equation-help.html Trigonometric Identity Equation http://www.mathhelpforum.com/math-help/trigonometry/115696-trigonometric-identity-equation.html Fri, 20 Nov 2009 05:07:04 GMT Hello!

Firstly, thank you for looking at my question! I am new here and although I seem to be able to pick up mathematical concepts rather well, this one problem is absolutely impossible for me to figure out. I know the answer - I just don't know how to get there! I created an image of my problem so its easier to see what I am talking about. Here is the equation:



Essentially, what I am able to get is this:

(sin^2 x)/(cos^2 x) = tan^2 x
-(tan x)/ -(cot x) = 1

tan^2 x - 1 does not equal tan^2 x

Any help would be super greatly appreciated, thank you very much!
-Joshua ]]> Trigonometry vulcangon http://www.mathhelpforum.com/math-help/trigonometry/115696-trigonometric-identity-equation.html Trig ratios, other trig mapping questions :/ Help greatly appreciated http://www.mathhelpforum.com/math-help/trigonometry/115663-trig-ratios-other-trig-mapping-questions-help-greatly-appreciated.html Fri, 20 Nov 2009 01:58:45 GMT Hey folks. Few questions here. A reply in detail ASAP = insanely appreciated. (Crying) 1. If sin a = y/r ; write the other 5 trigonometric ratios for a. 2. If csc B = -14/10 ; and B is in the fourth quadrant. Find the coordinate of the point on the end of the terminal arm, and its principle... Hey folks. Few questions here. A reply in detail ASAP = insanely appreciated. (Crying)

1. If sin a = y/r ; write the other 5 trigonometric ratios for a.

2. If csc B = -14/10 ; and B is in the fourth quadrant. Find the coordinate of the point on the end of the terminal arm, and its principle angle. Then find all the trigonometric ratios for B.

[t graph here]

(( I know it might be a challenge to find a graph but if you could upload one to imageshack or something or just explain it, It'd be great help ))

3. If (weird symbol, I think theta) * is third quadrant angle and cot * = -15/-8, find:

a) sin * cos *
b) cos^2 *
c) 4 cot *
d) cot * tan *

Once again thank you SO much for reading and helping! Need this for tommorow before I get behind! ]]> Trigonometry Luciffer http://www.mathhelpforum.com/math-help/trigonometry/115663-trig-ratios-other-trig-mapping-questions-help-greatly-appreciated.html Law of Cosines http://www.mathhelpforum.com/math-help/trigonometry/115620-law-cosines.html Thu, 19 Nov 2009 20:41:39 GMT Use the law of cosines to solve the triangle C=108° a=10 b=7 Use the law of cosines to solve the triangle

C=108°
a=10
b=7 ]]> Trigonometry ryno16 http://www.mathhelpforum.com/math-help/trigonometry/115620-law-cosines.html Verify this identity http://www.mathhelpforum.com/math-help/trigonometry/115615-verify-identity.html Thu, 19 Nov 2009 19:32:25 GMT \frac{ \frac{1}{cos x}}{ \ \frac{1}{cos x} - \frac{sin x}{cos x}} = sec x(sec x+ tan x) I want to do this without turning the 1/cos x into sec x or sin x/cos x into tan x in the initial problem. Thanks!!! \frac{ \frac{1}{cos x}}{ \ \frac{1}{cos x} - \frac{sin x}{cos x}} = sec x(sec x+ tan x)

I want to do this without turning the 1/cos x into sec x or sin x/cos x into tan x in the initial problem. Thanks!!! ]]> Trigonometry Godzilla http://www.mathhelpforum.com/math-help/trigonometry/115615-verify-identity.html Verifying Identities http://www.mathhelpforum.com/math-help/trigonometry/115606-verifying-identities.html Thu, 19 Nov 2009 18:14:32 GMT So I've been looking at this homework that's due tommorrow for a grade for the past hour and I can't seem to figure these out.

1. sin^3x - cos^3x = (1 + sinx cosx)(sinx - cosx)

2. (1/(siny - 1)) - (1/(siny + 1)) = -2sec^2y

3. 1 - 2sin^2r + sin^4r = cos^4r

4. tanu + (cosu/(1 + sinu)) = secu

5. (tanx + secx)/(secx - cosx + tanx) = cscx

If I could get a hint or something on how to do these I would appreciate it, I don't want to ask anyone to do my homework for me (although I won't complain if you show me the whole problem) but I don't even know where to start on these problems. Thanks! ]]> Trigonometry Skizye http://www.mathhelpforum.com/math-help/trigonometry/115606-verifying-identities.html sin a sinx+ b cosx http://www.mathhelpforum.com/math-help/trigonometry/115575-sin-sinx-b-cosx.html Thu, 19 Nov 2009 15:19:29 GMT Hey. The question is find the value of R and the value of A. sinx+ 2cosx = Rcos(x-A) i can find R which is square root of 5, but i keep getting 1.11 for A and the answer is 0,46 (radians) can anyone help? Hey.
The question is find the value of R and the value of A.

sinx+ 2cosx = Rcos(x-A)

i can find R which is square root of 5, but i keep getting 1.11 for A and the answer is 0,46 (radians)

can anyone help? ]]> Trigonometry Oasis1993 http://www.mathhelpforum.com/math-help/trigonometry/115575-sin-sinx-b-cosx.html Am I doing this wrong? http://www.mathhelpforum.com/math-help/trigonometry/115574-am-i-doing-wrong.html Thu, 19 Nov 2009 15:17:24 GMT I have to verify this identity algebraically:
sin x (1 - 2 cos^2 x + cos^4 x) = sin^5 x

So I have to make the left side equal the right,
My work so far:
sin x (sin^2 x cos^2 x + 4 coos x)
sin x (sin^2 x [1 - sin^2 x] + 4 cos^4 x)
sin x ([sin^2 x - sin^4 x] + 4 cos^4 x)
sin x ([sin^2 x + cos^4 x + 1] + 4 cos^4 x)
sin x (sin^2 x + 5 cos^4 x + 1)

Now I am stuck. Am I correct so far? If I am, what do I do next?
Any help is appreciated. ]]> Trigonometry iluvmathbutitshard http://www.mathhelpforum.com/math-help/trigonometry/115574-am-i-doing-wrong.html Obtuse Angle and Sine http://www.mathhelpforum.com/math-help/trigonometry/115546-obtuse-angle-sine.html Thu, 19 Nov 2009 10:21:42 GMT Hello!

This is a question I couldn't solve.

If A is an obtuse angle in a triangle and sin A = 5/13, calculate the exact value of sin 2A.

I would appreciate your help,
Amine :)
]]> Trigonometry Aminekhadir http://www.mathhelpforum.com/math-help/trigonometry/115546-obtuse-angle-sine.html Trig Help. http://www.mathhelpforum.com/math-help/trigonometry/115537-trig-help.html Thu, 19 Nov 2009 08:08:55 GMT I need help with the following equations to solve between 0 and 360°: 1. \sin2x = \frac{1}{2} 2. \sin^2x = \frac{1}{2} 3. \cos(x-30) = 1 4. \cos^2x = \frac{3}{2} I need help with the following equations to solve between 0 and 360°:

1. \sin2x = \frac{1}{2}

2. \sin^2x = \frac{1}{2}

3. \cos(x-30) = 1

4. \cos^2x = \frac{3}{2}

For 1, I've obtained x = 45°, 225°, 315°, 360°.
For 2, I've 30° and 75°.
For 3, hopeless.
For 4, no idea. ]]> Trigonometry Captcha http://www.mathhelpforum.com/math-help/trigonometry/115537-trig-help.html Prove an identity and solve an equation http://www.mathhelpforum.com/math-help/trigonometry/115511-prove-identity-solve-equation.html Thu, 19 Nov 2009 05:05:18 GMT Prove the following identity:

[tan(x)+cot(x)]/[sec(x)-tan(x)] = sec^2(x) + sec(x)tan(x)csc^2(x)


Solve the Following Expression:

(16/81)^[sin^2(x)] + (16/81)^[1-sin^2(x)] = (26/27)

I need to know HOW to do these as well as the answers, so if you could show your work that would be appreciated. Thanks! ]]> Trigonometry jhunt47 http://www.mathhelpforum.com/math-help/trigonometry/115511-prove-identity-solve-equation.html Exact Values http://www.mathhelpforum.com/math-help/trigonometry/115491-exact-values.html Thu, 19 Nov 2009 02:43:38 GMT Okay. I have a quick question. If I have a hypotnuse of 13, and I know an angle is squareroot3/2 (cos 30) how do I find out the EXACT length of the adjacent side? Okay. I have a quick question.

If I have a hypotnuse of 13, and I know an angle is squareroot3/2 (cos 30) how do I find out the EXACT length of the adjacent side? ]]> Trigonometry abc10 http://www.mathhelpforum.com/math-help/trigonometry/115491-exact-values.html