Wednesday
October 26, 2016

# Search: Trig. Law of Cosines

Number of results: 9,608

Math - Trig
What familiar formula can you obtain when you use the third form of the Law of Cosines c^2 = a^2 + b^2 - 2ab cos C and you let C = 90deg? What is the relationship between the Law of Cosines and this formula?
February 6, 2014 by McKenna Louise

Trig
Should the triangle be solved beginning with Law of Sines of Law of Cosines. Then solve the triangle. Round to the nearest tenth. a=16, b=13, c=10. Cosines A=93 degrees, B=54 degrees, C=33 degrees
March 7, 2008 by Jon

Trig. Law of Cosines
Show that any triangle with standard labeling... a^2+b^2+c^2/2abc = cos(alpha)/a + cos(beta)/b + cos(gamma)/c I don't get it. Can someone please help me. Start here with the law of cosines: a^2 = b^2 + c^2 -2bc Cos A b^2 = a^2 + c^2 -2ac Cos B c^2 = a^2 + b^2 - 2ab Cos C Add ...
December 12, 2006 by ashley

Trig - Law of sines and cosines
ABC is an equilateral triangle with side length 4. M is the midpoint of BC, and AM is a diagonal of square ALMN. Find the area of the region common to both ABC and ALMN. I drew the diagram but I don't know how to find the answer? I think it has something to do with the law of ...
November 19, 2013 by Sam

trig
I need to prove parallelogram law using the law of cosines. 2AB^2 + 2BC^2 = AC^2 + BD^2 Please, help me to do this.
December 7, 2011 by Evelina

Find the indicated angle è. (Use either the Law of Sines or the Law of Cosines, as appropriate. Assume a = 95 and c = 137(angle B=38). Round your answer to two decimal places.)

Math - Trig
Use the law of cosines to show that the measure of each angle of an equilateral triangle is 60deg. Explain your reasoning.
February 6, 2014 by McKenna Louise

Trig
Use the Law of Cosines to determine the indicated angle θ. (Assume a = 17, b = 10, and c = 20. Round your answer to one decimal place.)
March 2, 2016 by Courtney

Trig-Medians and law of cosines and sines
In triangle ABC, we have AB=3 and AC=4. Side BC and the median from A to BC have the same length. What is BC? Not making sense to me, I think the answer must be simple, but I don't know how to solve I applied the law of sines but to no avail. Help is appreciated, thanks.
November 20, 2013 by Sam

Trig
Should the triangle be solved beginning with Law of Sines of Law of Cosines. Then solve the triangle. Round to the nearest tenth. A=56 degrees, B=38 degrees, a=13. Sines. I get confused on the formula. I know C=86 degrees
March 7, 2008 by Jon

Trig - check my answers plz!
1. (P -15/17, -8/17) is found on the unit circle. Find sinΘ and cosΘ Work: P= (-15/17, -8/17) cosΘ = a value P = (a,b) sinΘ = b value Answer: cosΘ = -15/17 sinΘ = -8/17 2. Should the triangle be solved beginning with Law of Sines or Law of Cosines...
February 3, 2009 by Piper

law of cosines
law of cosines m<c=60, a=12,b=15 triangle
April 28, 2011 by Anonymous

Precalculus
I know I posted this before,but I did not learn it your way .....instead I drew a picture and use the law of cosines....is there a way you can show me the work using law of cosines?? A plane flies 30 mi on a bearing of 200 degrees and then turns and flies 40 mi on a bearing of...
December 12, 2013 by Anonymous

Calculus
A plane flying with a constant speed of 14 km/min passes over a ground radar station at an altitude of 7 km and climbs at an angle of 45 degrees. At what rate, in km/min is the distance from the plane to the radar station increasing 2 minutes later? I know you use law of ...
October 14, 2006 by Michael

geometry
If a triangle has sides of lengths a and b, which make a C-degree angle, then the length of the side opposite C is c, where c2 = a2 + b2 − 2ab cosC. This is the SAS version of the Law of Cosines. Explain the terminology. Derive an equivalent SSS version of the Law of ...
April 12, 2010 by hodna

Geometry
How do I find the mesurements of a isosceles triangle? I have the sides set as E=72 degrees, and the legs that come down are 15, and i have to find D and F..I have no clue how to do this. Or any idea of a formula to help with this. The two base angles are equal, and the sum of...
May 27, 2007 by Fonda

Trigonometry/Geometry - Law of sines and cosines
In most geometry courses, we learn that there's no such thing as "SSA Congruence". That is, if we have triangles ABC and DEF such that AB = DE, BC = EF, and angle A = angle D, then we cannot deduce that ABC and DEF are congruent. However, there are a few special cases in which...
November 21, 2013 by Sam

Trig
Can you show us how to use law of cosines to show that theta equals inverse cosine of (a^2 + b^2 -484)/(2ab) where a^2=(7+xcos a)^2 + (28-xsin a)^2 and b^2=(7+xcos a)^2 + (xsin a -6)^2? Thanks
April 17, 2012 by Lisa

Algebra 2
Using the information given about a triangle, which law must you use to solve the triangle? Law of Sines, Law of Cosines, or Neither. ASA SSS SAS AAA SSA AAS
February 13, 2012 by Katy

trigonometry
okay so in my review packet under the "calculator" section it says law of sines and law of cosines. i don't know what that means. i wikipedia-ed it but i don't understand what they are saying. Please help!
January 22, 2009 by Spencer

Trig.
I have answers for these problems, but I wanted to check if I had them right because I wasn't sure on some of them....Thanks. Solve the triangle: 1. a=4, b=8, alpha=30 deg. answer- beta=90 deg., gamma=60 deg., c=7 2. a=5, b=7, alpha=30 deg. answer- beta=44 deg., gamma=106 deg...
December 12, 2006 by ashley

Physics
i was woundering if you could point in the right direction i'm looking for very easy physics topics that makes use of the law of sines or the law of cosines Thanks
October 19, 2009 by Physics

math
solve each triangle using either the Law of Sines or the Law of Cosines. If no triangle exists, write “no solution.” Round your answers to the nearest tenth. A = 23°, B = 55°, b = 9 A = 18°, a = 25, b = 18
December 9, 2011 by Rick

trig
Express sin4xcos3x as a sum or differences of sines and cosines
February 21, 2013 by Fabian onyango ndege

Trigonometry
Law of Cosines a=4.7 b=3.2 c=5.2 Find B
November 17, 2015 by Shannon

Maths/Right Triangle
There must be a relationship (formula) between the lengths of the sides of a Right Triangle and the angles opposite these sides. Help Please. Mike. Look at the law os sines or cosines. Law of sines a/sin(A) = b/sin(B) = c/sin(C) Law of cosines a2 = b2 + c2 - 2bc cos(A) b2 = c2...
October 21, 2006 by Mike

Trig-Geometry - Law of sines and cosines
Hello everyone, I've been struggling on this problem for quite some time. It would be appreciated if you could help. Thanks. (The website is the diagram, it is a screenshot) In the diagram below, triangle ABC has been reflected over its median AM to produce triangle AB'C'. If ...
November 24, 2013 by Sam

Pre-Calc Helppp!!!
Find the indicated angle è. (Use either the Law of Sines or the Law of Cosines, as appropriate. Assume a = 110 and c = 136 (angle B=38) Round your answer to two decimal places.)
April 5, 2012 by Mike

law of cosines and sines
m<C=70,c=8,m<30 solve the triangle
April 28, 2011 by Anonymous

precal 2
use the law of cosines to solve the triangle a=55, c=72, b=25
July 31, 2011 by raven

Pre calculus
Why is it dangerous to use the law of sines to find an angle but is not dangerous to use the law of cosines? Please explain this thoroughly.
December 8, 2013 by Anonymous

Trigonometry
When using the Law of Cosines, how do I know if two triangles exist?
January 19, 2010 by Laurianne

precal 2
use the law of cosines to solve the triangle A=55 degree, c=10, b=3
July 29, 2011 by danielle

Math
a = 9, b = 3, and c = 11. Use the law of Cosines to solve B. My ans: 12.90 degs?
November 6, 2015 by Anonymous

math
The law of cosines can't be used when which of the following combinations of information is given?
June 24, 2013 by henna

Math
Use the law of cosines to find the angle Q between the given vectors. v = 3i + j w = 2i - j
March 30, 2010 by Hannah

Math
Given the points A(0,0), B(4, 3) and C(2,9), what is the measure of angle ABC? Using Law of Cosines.
July 21, 2013 by jasmine

Pre-Cal
Use the law of cosines to find the angle of Q between the given vectors. v=3i + j w=2i - j
March 28, 2010 by Hannah

Trigonometry
Using the Law of Cosines, how can I show that the measure of each angle of an equilateral triangle is 60 degrees?
February 10, 2014 by McKenna Louise

Calculus
Hello! I need help with this problem, its been irritating me for days! Any help would be greatly appreciated! Here’s the question.. The minute hand on a watch is 8 mm long and the hour hand is 4 mm long. How fast is the distance between the tip of the hands changing at 10:00 (...
September 30, 2016 by Mia

Use the law of cosines to find the angle Q between the given vectors. v = 3i + j w = 2i - j
March 31, 2010 by Hannah

trig 26
simplify to a constant or trig func. 1. sec ²u-tan ²u/cos ²v+sin ²v change expression to only sines and cosines. then to a basic trig function. 2. sin(theta) - tan(theta)*cos(theta)+ cos(pi/2 - theta) 3. (sec y - tan y)(sec y + tan y)/ sec y combine fractions and simplify to a...
March 14, 2010 by hilde

trig/math
3. Draw vectors u and v tail-to-tail so that they make a è-degree angle. Draw the vector u − v, the third side of the triangle, and check to see that it points in the right direction. (a) Solve for cos è using the SSS version of the Law of Cosines, expressing all lengths...
April 18, 2010 by sarah

geometry
I am studying for my GRE exam into grad school and it's been a very long time since I've done geometry. I have a problem to which I need to solve for the area of a triangle but I do not have the base. I do have all angles but I cannot remember how to convert angles into their ...
July 10, 2006 by Kaytee

Law of cosines
A tree on a hillside casts a shadow 215 ft down the hill. If the angle of inclination of the hillside is 22 degree to the horizontal and the angle of elevation of the sun is 52 degreess, find the height of the tree. TIA sorry this is law of sines. sorry for the confusion.
March 27, 2007 by Jen

Law of Cosines
i.imgur. com / CvoC1sB.jpg I'm confused about how to submit a link, but attached is the problem because there is a diagram. I did part of it, but I'm stuck! I put in spaces.
September 13, 2014 by Jeff

maths(direction cosines of vectors)
find the direction cosines of the vector joining the two points (4,2,2,) & (7,6,14) (this is new to me, used to think it was just one point not two.)
March 9, 2015 by Francis

Alge2/trig
Should the triangle be solved beginning with Laws of Sines or Laws of Cosines. Then solve the triangle and round to the nearest tenth. a=16, b=13, c=10
March 14, 2009 by Sha

Pre calculus
For the most part, will a law of cosines always be one triangle? As in one triangle to solve?
March 26, 2014 by Luis

3 D - geometry (direction of cosines)
Find the angle between the lines between the lines whose direction cosines satisfy the equations l + m + n = 0 and 2mn + 3nl - 5lm =0.
March 10, 2012 by uma

Calculus
use law of cosines to show that theta equals inverse cosine of (a^2 + b^2 -484)/(2ab) where a^2=(7+xcos a)^2 + (28-xsin a)^2 and b^2=(7+xcos a)^2 + (xsin a -6)^2
April 16, 2012 by Lisa

Math
If a 14-ft ladder leans against a building, with an angle of elevation of 70°, how far up the building will the ladder reach? I believe this requires law of cosines but otherwise I am lost.
December 11, 2015 by Nick

Math
Use the law of cosines to solve ABC with A=126.3, b=45, and c=62.5 I did all the work to find a but my problem is finding B a=96.2 Sin(B)=45sin126.3/96.2 B=Sin^-1(45sin126.3/96.2) It's not going through in my calculator
October 2, 2008 by House

pre calc
the longest side of a triangle is 34 feet. the measures of two angles of the triangle are 40 and 65 degrees. find the lengths of the other two sides using law of sines and cosines
April 28, 2011 by g

Math Work
I know that I'm using the Law of Cosines, but I'm confused on how to solve. I have to also round my answers to the nearest tenth for degrees and to the nearest hundredth for sides Given: A= 55 degrees b=3 c=10 Find: a= B= C=
February 24, 2015 by Amber

Homework (Math)
I know that I'm using the Law of Cosines, but I'm confused on how to solve. I have to also round my answers to the nearest tenth for degrees and to the nearest hundredth for sides. Given: A= 55 degrees b=3 c=10 Find: a= B= C=
February 25, 2015 by Taylor

Algebra 2 with trigonometry
A baseball diamond is a square 90 feet on a side. The pitcher's mound is 60.5 feet from home. How far does the pitcher have to run to cover first? (we are using the LAW OF SINES AND COSINES)
May 6, 2010 by T

Math
A ramp 10 feet in length rises to a loading Platform that is 4 feet off the ground. What is the angle of elevation of the ramp in degrees? Do I use the law of cosines? When I do though I'm getting a little confused what to do.
August 20, 2011 by Jason

math
A ramp 10 feet in length rises to a loading Platform that is 4 feet off the ground. What is the angle of elevation of the ramp in degrees? Do I use the law of cosines? When I do though I'm getting a little confused what to do.
August 21, 2011 by Jason

My Friend Needs Help With a Calc Problem.
how does five degrees east of north keep a plain going north when the wind pushes the plain four point six degrees west of north? This is not calculus. It is a vector problem. THe wind is pushing the plane west. If you need the solution, to find the direction of the wind, a ...
October 12, 2006 by Sarah

Calculating distance(law of cosines)
Observers P and Q are located on the side of a hill that is inclined 32 degrees to the horizontal as shown(picture given). The observer at P determines the angle of elevation to a hot air balloon to be 62 degrees. At the same instant the observer at Q measures the angle of ...
March 27, 2007 by Jen

Math - Trig
Hi I have a Trig question that i don't understand, can someone please explain how to solve for it using cosine law?? A Clock with a radius of 15 cm has an 11 cm minute hand and a 7 cm hour hand. How far apart, to the nearest centimetre, are the tips of the hands at each time? ...
April 30, 2008 by Mark

MATH
Using the Law of Cosines for vectors, give a vector proof that if quadrilateral ABCD is a rhombus, diagonal AC bisects <BAD. As part of your proof include a carefully drawn figure a statement of what is given, and a statement of what you are proving. I need help with this. ...
November 2, 2011 by Pam

Math
A baseball diamond is a square sides 22.4 m. The pitcher's mound is 16.8 m from home plate on the line joining home plate and second base.. How far is the pitcher's mound from first base? (we are using the LAW OF SINES AND COSINES)
October 1, 2012 by Kailey

Precalc
A tower is supported by a guy wire 610 ft long. If the wire makes an angle of 69 degrees with respect to the ground and the distance from the point where the wire is attached to the ground and the tower is 125 feet. a) State if the law of sines or cosines should be used for ...
January 20, 2013 by Mickey

Pre-calc
prove the identity: (cosx)(tanx + sinx cotx)=sinx+cos(squared)x i need steps to show how i got the answer generally, it is a good idea to change all trig ratios to sines and cosines, and start with the more complicated-looking side. so.... LS = cosx(sinx/cosx + sinx(cosx/sinx...
May 6, 2007 by Stacey

geometry
Use the Law of Cosines to solve the problem. A ship travels due west for 83 miles. It then travels in a northwest direction for 111 miles and ends up 165 miles from its original position. To the nearest tenth of a degree, how many degrees north of west did it turn when it ...
March 18, 2016 by Steve

MATH 112
two planes leave an airport at the same time. Their speeds are 320 miles per hour and 380 miles per hour. If the angle between their courses is 112 degrees, how far apart are they after two hours? (The hint is using the law of cosines)
November 20, 2012 by diego sanchez

Algebra II/ Trig
Should the triangle be solved beginning with Laws of Sines or Laws of Cosines. Then solve the triangle and round to the nearest tenth. a=16, b=13, c=10 I got this answer but it is wrong and don't understand where I made the mistake. a=16, b=13, c=10 a^2=b^2+c^2-2bc Cos A 16^2=...
March 14, 2009 by Sha

Pre calculus
A tugboat is traveling at 30 miles per hour at a compass heading of 38 degrees. The current is from the direction of 125 degrees moving at 7 mph. Find the resultant speed and the direction of the boat. I understand the concept and that I must use the law of cosines. I got 30^2...
February 16, 2015 by Hanna

Physics
At the entrance channel of a harbor, the tidal current has a velocity of 4.94 km/hr in a direction 23.2° south of east. Suppose a ship caught in this current has a speed of 15.6 km/hr relative to the water. If the helmsman keeps the bow of the ship aimed north, what will be ...
October 18, 2007 by Lindsay

government
Which branch of the law regulates wrongful acts involving injury to one’s person, property, or reputation in a situation not covered by the terms of a contract? A. common law B. tort law C. civil law D. contract law
March 8, 2012 by Johana

government
Which branch of the law regulates wrongful acts involving injury to one's person, property, or reputation in a situation not covered by the term of a contract? A. common law B. tort law C. civil law D. contract law
April 2, 2012 by Charlette

math - trig
Why cant we solve an oblique triangle with the Law of Sines if we are given SAS?
February 10, 2014 by McKenna Louise

bus law
What is the chronological order of the major legislation that makes up the history of employment law in this country? For each law, state the social problem the law was designed to address, and discuss how employment law has affected the workplace in the last two decades.
September 2, 2010 by kash

Science-Chemistry
1. What is Charles’s law? • State the definition of the law in words. • What are the assumptions of Charles’s law? • Write mathematical equations that represent the law. • What can you do with Charles’s law? • Using a gas-filled balloon as an example, describe what happens to ...
May 31, 2013 by Help needed.... Danielle

Math - Trig
Explain why we cannot solve an oblique triangle with the Law of Sines given SAS.
February 6, 2014 by McKenna Louise

MATH!!!!
The CN Tower is 553m high. A person in a boat on Lake Ontario, at a point B due south of the tower, observes the top (T) of the tower at an angle of elevation of 8 degrees. At the same time, another person, at a point C on a bearing {S 85 degrees E } from the towerobserves an ...
September 26, 2006 by Kaitlin

Government Law question
What kind of law is it when judges make the law by their decisions on the bench? ___ Law
January 14, 2013 by Allyson

Trig
I was just wondering if anyone can explain the Law of Sines- "Ambiguity Case" to me, in a way that is easy to understand.
November 15, 2008 by Ariel

Law
Research and identify a labor law that is specific to your state. Share a brief summary of the law with us and discuss why you believe this law is or is not important to the employer-employee relationship.
November 29, 2013 by Mattiazz

trig
Use the Law of Sines to solve each triangle. P=110 degrees p=125, r=200 in triangel PQR
November 26, 2011 by Tyler

PreCalc - Vectors
An airplane is flying with an airspeed of 660 Kilometers per hour. The wind is blowing from 345 degrees at 35 km/h. What direction should the airplane take so that, with the wind, the plane will be flying in a direction of 72 degrees? I can compute airspeed and actual ...
May 3, 2011 by Joe

precalculus
A force of 369 lbs makes an angle of 18 degrees 20 minutes with a force 427 lbs. Find the angle made by the equilibrant with the 369 lbs force. I know I can find this using the law of cosines, but I think my teacher wants me to use some vector thing, but I do not know how to ...
May 11, 2008 by Iamxe

math
vector a is 8 ft., vector b is 2 ft, and theta is at 41 degrees. find the resultant and the direction. I drew a diagram that shows a connecting with b (head to tail), and they make the 41 degrees. I use law of cosines and got about 6ft, which doesn't sound right to me. my work...
November 18, 2009 by Anonymous

legal and ethical issues
select a current or proposed law that impacts the delivery of human services what reliable resources are availiable to learn about the implications of this law? What is the purpose or rationale of the law? How will the law effect da-t-day operations within human service ...
June 2, 2008 by Tiff

Physics
Two dogs pull horizontally on ropes attached to a post; the angle between the ropes is 65.0. Dog exerts a force of 256 and dog exerts a force of 344 . A) Find the magnitude of the resultant force. B) Find the angle the resultant force makes with dog 's rope. You can do this ...
November 4, 2006 by kuwaiti

calculus
A triangle ABC has sides of length AB = 3 inches and AC = 4 inches. Let t denote the angle at vertex A, and let s denote the length of the remaining side BC. If t increases at the rate of 2 radians per second, at what rate (in inches per second) does s change at the instant ...
March 5, 2011 by Tori

Civics
In the case The Senate Of Tennessee V. John Thomas Scopes, high school biology teacher John Scopes was accused of teaching content that violated a Tennessee law that stopped public school teachers from teaching evolution. Scopes voted this law , but felt his right to free ...
January 18, 2015 by jeje

Government
i think it is answer ( b ), can someone make sure What is the difference between criminal and civil law? a) There is no difference. b) The standard of guilt is higher in criminal law than it is in civil law c) The government is always involved in civil law but never in ...

Chemisrty
Determine which law is appropriate for solving the following problem. What volume will 1.56 liters of a gas at 27°C and 745 mmHg of pressure occupy at 100°C and 700 mmHg of pressure? Law used: Boyle's Law Charles' Law Combined Gas Law
October 19, 2011 by Angel

bioethics
what is law natural law eternal law human positive law what is conscience different kinds of conscience pls need an answer thanks
June 20, 2011 by joyce

Law
Hi there! I have totally got to find out how the Aussie Law is similar to the US law. Anyway I DO like know that like Oz follows England law mainly but that isn't what I need. Bushells of Thanks Minnie
April 25, 2008 by Minnie

what is the chronological order of the major legislation that makes up the history of employment law in this country? for each law, state the social problem the law was designed to address and whether the law has solved the problem.
April 27, 2011 by Sean

Precalculus
In most geometry courses, we learn that there's no such thing as "SSA Congruence". That is, if we have triangles ABC and DEF such that AB = DE, BC = EF, and angle A = angle D, then we cannot deduce that ABC and DEF are congruent. However, there are a few special cases in which...
February 24, 2014 by John

geometry
A segment that is a units long makes a C-degree angle with a segment that is b units long. In terms of a, b, and C, find the third side of the triangle defined by this SAS description. You have done numerical versions of this question. Start by finding the length of the ...
April 11, 2010 by sally

Trigonometry/Geometry
In most geometry courses, we learn that there's no such thing as "SSA Congruence". That is, if we have triangles ABC and DEF such that AB = DE, BC = EF, and angle A = angle D, then we cannot deduce that ABC and DEF are congruent. However, there are a few special cases in which...
November 19, 2013 by Sam

AP CALC. AB
Two sides of a triangle have lengths 13 m and 17 m. The angle between them is increasing at a rate of 5 degrees/ min. How fast is the length of the third side increasing when the angle between the sides of fixed length is 60 degrees/min? Round the result to the nearest ...
November 29, 2014 by Jacke

Math
1. Find the value of Sin^-1(-1/2) a. -30 degrees b. 30 degrees c. 150 degrees d. 330 degrees 2. Find the exact value of cos(-420 degrees) a. -1/2 b. 1/2 c. sqrt of 3/2 d. -sqrt of 3/2 3. p(-9/41, 40/41) is located on the unit circle. Find sin theta. a. 40/41 b. -9/41 c. -9/40 ...
April 5, 2008 by Belden

bus/415
What is the chronological order of the major legislation that makes up the history of employment law in this country? For each law, state the social problem the law was designed to address, and discuss how employment law has affected the workplace in the last two decades.
August 17, 2010 by Shelly

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