# trigonometry

Most popular questions-
## Trigonometry

If A + B + C = 180°, Prove that Cos²A + Cos²B + Cos²C = 1-2cosAcosBcosC

*asked by Kewal on February 10, 2012* -
## Trigonometry

The populations, P, of six towns with time t in years are given by: I) P=1000(1.08)^t II) P= 600(1.12)^t III) P = 2500(0.9)^t IV) P=1200(1.185)^t V) P=800(0.78)^t VI) P=2000(0.99)^t a. Which towns are growing in size? Which are shrinking? b. Which town is

*asked by Lee on January 15, 2013* -
## Trigonometry

A communications tower is located at the top of a steep hill, as shown. The angle of inclination of the hill is 58°. A guy wire is to be attached to the top of the tower and to the ground, 50 m downhill from the base of the tower. The angle α in the

*asked by Liz on October 1, 2014* -
## TRIGONOMETRY

Express tan theta in terms of cosec theta

*asked by MaThS on March 26, 2016* -
## Trigonometry

A billiard ball is struck by a cue. it travels 100 centimeters before ricocheting off a rail forming a 45 degree angle and traveling another 120 centimeters into a corner pocket. How far apart is the initial position of the ball from the corner pocket the

*asked by Hailey Lepire on May 15, 2017* -
## Trigonometry

Karla is riding vertically in a hot air balloon, directly over a point P on the ground. Karla spots a parked car on the ground at an angle of depression of 30o. The balloon rises 50 meters. Now the angle of depression to the car is 35°. How far is the car

*asked by Allison on October 26, 2012* -
## trigonometry

Prove: tan2x+sec2x = cosx+sinx/ cosx-sinx

*asked by Beatriz on January 4, 2010* -
## Trigonometry

The number of hours of daylight in a city in the northern hemisphere shows periodic behavior over time. - The average number of daylight hours is 12 - The maximum number of daylight hours is 14.4 - The period is 365 days - The day with the least sunlight

*asked by Max on March 2, 2018* -
## Trigonometry

a bicycle with 24inch diameter wheels is traveling at 15mi/hr. a) Find the angular speed of the wheels in rad/min. b)How many revolutions per minute do the wheels make?

*asked by Dan on April 7, 2015* -
## trigonometry

A tree is broken over by the wind. It forms a right angled triangle with the ground. If the broken part makes an angle of 60° with the ground and the top of the tree is now 20m from its base, how tall WAS the tree?

*asked by MaThS on March 26, 2016* -
## trigonometry

The sprockets and chain of a bicycle are shown in the figure. The pedal sprocket has a radius of 4 in., the wheel sprocket a radius of 2 in., and the wheel a radius of 13 in. The cyclist pedals at 45 rpm. (a) Find the angular speed of the wheel sprocket.

*asked by monic on November 29, 2012* -
## trigonometry

Prove : 1 + Sin2A/ Cos2A = CosA + SinA / CosA- SinA

*asked by clive on May 5, 2015* -
## Trigonometry

Prove: 1-tanx/1+tanx=1-sin2x/cos2x

*asked by Xiumin on October 30, 2014* -
## Trigonometry

A batter hits a ball with an initial velocity v0 of 100 feet per second at an angle theta to the horizontal. An outfielder catches the ball 200 feet from home plate. Find theta if the range of a projectile is given by the formula R=1/32v0 squared times sin

*asked by Anonymous on February 20, 2008* -
## Trigonometry

A clown is juggling at a circus. The path of a ball is given by the parametric equations x=2 cos T + 2 and y = 3 sin T + 3. In what direction is the ball moving? Up and to the right counterclockwise down and to the right clockwise After graphing it and

*asked by Nina on May 29, 2017* -
## trigonometry

the bases of a trapezoid are 22 and 12 respectively. The angles at the extremities of one base are 65 degree and 40 degree respectively find the two legs. Answer using law of sines pls

*asked by joe on February 10, 2012* -
## Trigonometry

A painter needs to cover a triangular region 62 meters by 68 meters by 70 meters. A can of paint covers 70 square meters. How many cans will be needed?

*asked by Kim on April 24, 2009* -
## Trigonometry

If the shadow of a building increases by 10 meters when the angle of elevation of the sun rays decreases from 70o to 60o, what is the height of the building?

*asked by Allison on October 26, 2012* -
## TRIGONOMETRY

Evaluate the expressions: a) arctan(-sqrt(3)) a) Arctan(-sqrt(3)) So, I know how to find the answers with a calculator, but how do I find it step by step?

*asked by Kate on May 18, 2013* -
## Trigonometry

An observer in a lighthouse 350 feet above sea level observes two ships directly offshore. The angles of depression to the ships are 4° and 6.5°. How far apart are the ships?

*asked by AwesomeGuy on February 4, 2013* -
## Trigonometry

Simplify #1: cscx(sin^2x+cos^2xtanx)/sinx+cosx = cscx((1)tanx)/sinx+cosx = cscxtanx/sinx+cosx Is the correct answer cscxtanx/sinx+cosx? Simplify #2: sin2x/1+cos2X = ??? I'm stuck on this one. I don't know what I should do. Simplify #3:

*asked by Anonymous on February 20, 2012* -
## Trigonometry

A vertical pole 40 feet tall stands on a hillside that makes an angle of 17 degrees with the horizontal. Approximate the minimum length of cable that will reach the top of the pole from a point on the hillside 72 feet downhill from the base of the

*asked by Bailey on November 3, 2014* -
## Trigonometry

A plane is 160 miles north and 85 miles east of an airport. If the pilot wants to fly directly to the airport, what bearing would be taken?

*asked by AwesomeGuy on February 4, 2013* -
## Trigonometry

Evaluate arctan(cot10Pi/9) sec(arccos(-1/6) csc(arcsec(5/3) sin(2 arccos(sqrt5/5)

*asked by Liv on November 27, 2016* -
## trigonometry

find acute angle A and B satisfying secAcotB-secA-2cotB+2=0

*asked by ajit yadav on May 14, 2013* -
## trigonometry

The wheels of a car have radius 11 in. and are rotating at 800 rpm. Find the speed of the car in mi/h. mi/h

*asked by monic on November 26, 2012* -
## Trigonometry

How do I prove that sin(x+y)-sin(x-y)=2cosx siny

*asked by Rene on April 5, 2013* -
## trigonometry

as you walk on a straight level path toward a mountain, the measure of the angle of elevation to the peak from one point is 33 degrees. From a point 1000 feet closer, the angle of elevation is 35 feet. How high is the mountain?

*asked by noel chavez on January 29, 2013* -
## trigonometry

tanA - sin A /sin^2A= tan A / 1 + cosA Please prove this

*asked by Venkatesh on March 22, 2016* -
## Trigonometry

A building 200 feet tall casts an 80 ft long shadow. If a person looks down from the top of the building which of the following is the measure of the angle between the end of the shadow and the vertical side of the building to the nearest degree? I

*asked by Ben on February 23, 2017* -
## Trigonometry

two airplanes leave an airport at the same time one hour later they are 189km/hr apart. if one plane traveled 168km/hr and the other traveled 244km/hr for the hour what is the angle between their flight path

*asked by Mark on June 8, 2016* -
## Trigonometry

Prove identity. Sec(pi-x)=-sec x

*asked by ALISON on October 23, 2011* -
## Trigonometry

Points A and B 1000 meter apart are plotted on a straight highway running east and west. from A, the bearing of tower C is N32*W and from be, the bearing of C is N64*E. approximate the shortest distance of the tower from the highway. please explain........

*asked by Roy on September 9, 2012* -
## trigonometry

Filiz is walking at a bearing of 300°. When she has traveled 20 meters, how far west from her starting point is she? Round to the nearest tenth

*asked by sabrina on July 27, 2017* -
## Trigonometry

Given the equation for simple harmonic method d=1/12 sin(60 pi t) answer the following questions: b)Find the frequency i got 60pi c)Calculate the value of d when t=3 d)Determine the least positive value of t for which d=0.

*asked by Ryan on March 24, 2016* -
## Trigonometry

Given that sin^2x = 4/13, what is the cos^2x? I am so lost. I need to show my work. Please help. THANK YOU!

*asked by Emma on August 30, 2017* -
## Trigonometry

A ship is 50 miles east and 35 miles south of port. If the captain wants to sail directly to port, what bearing should be taken?

*asked by AwesomeGuy on February 4, 2013* -
## Trigonometry

If the terminal side of angle theta passes through point (-3, -4), what is the valuse of sec theta? 1) 5/3 2) -5/3 3)5/4 4)-5/4

*asked by Jana on April 17, 2016* -
## Trigonometry

A plane leaves airport A and travels 560 miles to airport B at a bearing of N32E. The plane leaves airport B and travels to airport C 320 miles away at a bearing of S72E. Find the distance from airport A to airport C.

*asked by Love on February 10, 2016* -
## Trigonometry

A cat, sitting on top of a tree, spots a dog and a firefighter, both on flat ground below. From the cat's point of view, the dog is 10m south, at an angle of depression of 65 degrees, and the firefighter is some distance east of the tree, at an angle of

*asked by Alexis on December 13, 2015* -
## Trigonometry

Prove that cos(A+B) + sin(A-B) = 2sin(45°+A)cos(45°+B)

*asked by Kewal on December 31, 2011* -
## Trigonometry

1. 4sin^2x=3tan^2x-1 2. 8cos^2x-4cos^4x=3 3. 3secx-cosx=2

*asked by Michael on June 5, 2010* -
## Trigonometry

change 8 cis 240 degrees to rectangular form

*asked by steve on December 9, 2013* -
## trigonometry

a clock has a dial face of 12 inches radius the minute hand is 9 inches while the hour hand is 6 inches the plane of rotation of the hour hand is 2 inches above the plane of rotation of the minute hand. Find the distance between the tips of the minute and

*asked by Rose on March 18, 2014* -
## Trigonometry

an airplane over the pacific sights an atoll at a 11 degrees angel angle of depression. if the plane is 410 m above water how many kilometers is it from a point 410 m above the atoll

*asked by :) on March 5, 2012* -
## Trigonometry

Two observers who are 2 miles apart on a horizontal plane observe a balloon in a same vertical plane with themselves. the angles of elevation are 50 degrees and 65 degrees respectively. find the height of the balloon,(a)if it is between the observers;(b)if

*asked by Jam on August 2, 2014* -
## Trigonometry

Surveying A surveyor wishes to find the distance across a swamp. The bearing from A to B (Segment AB is opposite side of triangle) is N 32° W. The surveyor walks 50 meters from A to C, and at the point C the bearing to B is N 68° W. (Segment AC is

*asked by AwesomeGuy on February 4, 2013* -
## trigonometry

a wheel is rotating at 8 radians/sec, and the wheel has a 47 inch diameter. to the nearest foot, what is the velocity of a point on the rim in ft/min? all i know is that you have to use the formula v=r.w

*asked by y912f on January 7, 2009* -
## Trigonometry

A variant on the carousel at a theme park is the swing ride. Swings are suspeneded from a rotating platform and move outward to form an angle x with the vertical as the ride rotates. The angle is related to the radial distance,r, in metres, from the centre

*asked by Vikki on November 13, 2014* -
## Trigonometry

Use the trigonometric subtraction formula for sine to verify this identity: sin((π / 2) – x) = cos x

*asked by Tim on May 10, 2015* -
## Trigonometry

Having trouble with true/false questions in Trigonometry. They read as follows - True or False: For a trigonometric function, y=f(x), then x=F^-1(y). Explain your answer. True or False: For a one to one function, y=f(x), then x=f^-1(y). Explain your

*asked by Veronica on March 24, 2011* -
## trigonometry

A Wheel of radius 14in. is rotating 0.5 rad/sec. What is the linear speed v, the angular speed in RPM ( rev per min), and the angular speed in deg/sec?

*asked by Dan on April 8, 2015* -
## Trigonometry

if cos x=2/3 and x is in quadrant 4 find tan(x/2),sin(x/2),and cos(x/2) i got sin(x/2)=squr 1/6 tan(x/2)=squr 2/6 cos(x/2)=squr 5/6

*asked by Ryan on April 5, 2016* -
## trigonometry

A truck with 48-in.-diameter wheels is traveling at 45 mi/h. (a) Find the angular speed of the wheels in rad/min. rad/min (b) How many revolutions per minute do the wheels make? rev/min

*asked by monic on November 26, 2012* -
## Trigonometry

Statuary Hal is an elliptical room in the U.S. Capitol. Teh room is also called the Whispering Gallery because a person standing at one focus of the room can hear even a whisper spoken by a person standing at the other focus. Statuary Hall is 46 ft. wide

*asked by Lindsey on December 19, 2011* -
## Trigonometry

Outside temperature over a day can be modeled as a sinusoidal function. Suppose you know the high temperature of 95 degrees occurs at 3 PM and the average temperature for the day is 80 degrees. Find the temperature, to the nearest degree, at 8 AM

*asked by Julie on November 1, 2016* -
## Trigonometry

A hinged crane which measures 19m makes an angle of 50° with the ground. A malfunction causes the lock on the hinge to fail and the top part (of 14.6m) of the crane swings down. How far from the base of the crane does the top hot the ground.

*asked by Jack on May 19, 2016* -
## Trigonometry

If sinA + sinB = a and cosA + cosB = b, find the value of tanA-B/2

*asked by Kewal on January 9, 2012* -
## Trigonometry

Prove that 1-cosA+cosB-cos(A+B)/1+cosA-cosB-cos(A+B) = tanA/2cotA/2

*asked by Kewal on January 4, 2012* -
## Trigonometry

If sin(x) = 4cos(x), then what is (sin(x))*(cos (x))?

*asked by Katie on April 4, 2016* -
## Trigonometry

The height of building AB is 100 feet. The height of building CD is 50 feet. The buildings are on opposite sides of an avenue that is 90 feet wide. From a point E on the avenue, the measure of the angle of elevation to B is 55º. Determine the distance

*asked by Quinn on November 29, 2018* -
## trigonometry

A truck with 48-in.-diameter wheels is traveling at 55 mi/h. Find the angular speed of the wheels in rad/min, *hint convert miles to inches & hours to minutes: __rad/min How many revolutions per minute do the wheels make?__ rpm

*asked by marie darling on March 15, 2013* -
## Trigonometry

An airplane is headed on a bearing of 140° with an air speed of 500 miles per hour. The course has a bearing of 128°. The ground speed is 580 miles per hour. Find the drift angle, the wind direction, and the wind speed.

*asked by John on March 5, 2018* -
## Trigonometry

while standing at the left corner of the schoolyard in front of her school, Suzie estimates that the front face is 8.9m wide and 4.7m high. from her position, Suzie is 12m from the base of the right exterior wall. she determines that the left and right

*asked by Franny on December 11, 2011* -
## Trigonometry

a flagpole 25 feet tall stands on a top of a building. from a point in the same horizontal plane with the base of the building. The angle of elevation of the top and the bottom are 61°30' and 56°20' respectively. How high is the building?

*asked by Paul on July 11, 2013* -
## trigonometry

A wheel with a 21-inch diameter is turning at the rate of 58 revolutions per minute. To the nearest inch, what is the velocity of a point on the rim in inches/minutes? 3879 inches/minutes is my answer correct??

*asked by y912f on January 17, 2009* -
## Trigonometry

Use the equation mg sin A = umg cos A to determine the angle at which a waxed wood block on an inclined plane of wet snow begins to slide. Assume the coefficient of friction, u, is 0.17.

*asked by TeeKay on October 17, 2014* -
## trigonometry

a submarine at the surface of the ocean makes an emergency dive, its path making an angle of 21 degree with the surface. if it goes 300m long its download path, how deep will it be? what horizontal distance is it from its starting point?

*asked by riza on December 10, 2012* -
## Trigonometry

Having trouble with true/false questions in Trigonometry. They read as follows - True or False: For a trigonometric function, y=f(x), then x=F^-1(y). Explain your answer. True or False: For a one to one function, y=f(x), then x=f^-1(y). Explain your

*asked by Veronica on March 24, 2011* -
## Trigonometry

Write the trigonometric expression as an algebraic expression. 1.) SIN(ARCSIN X+ARCCOS X) ANSWER: 1 2.) SIN(ARCTAN 2X-ARCCOS X) ANSWER: 2x²-SquareRoot of 1-x²/Square Root of 4x²+1.

*asked by AwesomeGuy on February 21, 2013* -
## Trigonometry

How do I find all solutions to: tanx+3cotx=4? The answer choices are: a.) x=arctan3+nPi b.) x=arccot3+nPi

*asked by Grace on January 1, 2010* -
## Trigonometry

A carnival Ferris wheel with a radius of 7 m makes one complete revolution every 16 seconds. The bottom of the wheel is 1.5 m above the ground. The ride starts at the bottom. Find the sinusoidal function that models this Ferris wheel in terms of time (t)

*asked by Tabitha on January 14, 2011* -
## Trigonometry

Given \tan \theta = -\frac{4}{3}, where \frac{\pi}{2} < \theta < \pi, what is the value of \frac{1}{\sin \theta + \cos \theta}?

*asked by Jason on March 27, 2013* -
## trigonometry

How to solve a vertical pole 8 feet tall cast a shadow 5 feet long on level ground.find the angle which the rays of the sun makes with the horizontal.

*asked by cyjel on April 4, 2017* -
## Trigonometry

Please review and tell me if i did something wrong. Find the following functions correct to five decimal places: a. sin 22degrees 43' b. cos 44degrees 56' c. sin 49degrees 17' d. tan 11degrees 37' e. sin 79degrees 23'30' f. cot 19degrees 0' 25'' g. tan

*asked by Anon on January 1, 2011* -
## trigonometry

A race car is driven around a circular tract at a constant speed of 180 miles per hour. If the diameter of the track is 1/2 miles, what is the angular speed of the car? Express your answer in revolutions per hour. I know the answer is 114.59 revolutions

*asked by michelle on May 1, 2007* -
## Trigonometry

Point P is located at the intersection of the unit circle and the terminal side of angle theta in standard position. Find the coordinates of P to the nearest thousandth. theta = -105degrees Please explain the steps. I'm completely stuck.

*asked by A on June 1, 2017* -
## trigonometry

a lighthouse A bears N 36 degree 20 minutes E at a ship S. after sailing 2.75 km in the direction N 78 degree 50 minutes E to point T, the bearing of the lighthouse becomes N 8 degree 30 minutes E. find the distance from A to T.

*asked by frances on March 22, 2017* -
## Trigonometry

From an observation tower that overlooks a small lake, the angles of depression of point A, on one side of the lake, and point B, on the opposite side of the lake are, 7degrees and 13degrees, respectively. The points and the tower are in the same vertical

*asked by Marika on January 2, 2013* -
## Trigonometry

A plane is headed due east with airspeed of 240 mph. if a wind at 40 mph is bloiwing from the north , find the ground speed of the plane.

*asked by Roy on September 9, 2012* -
## Trigonometry

A calculator is broken so that the only keys that still work are the sin, cos, tan, cot, sin^-1, cos^-1, and tan^-1 buttons. The display initially shows 0. In this problem, we will prove that given any positive rational number q, show that pressing some

*asked by Sam on October 31, 2013* -
## Trigonometry

a boat travels on a course of bearing n 37 10' W for 79.5 miles. How many miles north and how many miles west has the boat traveled?

*asked by Mark on September 11, 2015* -
## trigonometry

You are standing on the equator of the earth (radius 3960 miles). a) what is your linear speed in miles per hour? b) what is the angular speed in radians per hour?

*asked by Michael on April 8, 2015* -
## trigonometry

The angle of elevation of the top of a tower to point A on the ground is 61 degrees. At point B it is 600 feet farther from the base, in line with the base and the first point and in the same plane, the angle of elevation is 32 degrees. Find the height of

*asked by berriengk on March 18, 2010* -
## Trigonometry

a 20ft. ladder is leaning against a wall so that the foot of the ladder is 9ft. from the buss of the wall what angle does the ladder make with the ground? what is the distance from the top of the ladder to the base of the house? based in trigonometry

*asked by Ara Jane on November 21, 2015* -
## trigonometry

if tan theta = 1/7 and tan phi= 1/3 then prove that cos 2 theta= sin 4 phi

*asked by ipshita on May 16, 2014* -
## Trigonometry

Find the angle of elevation of the sun when a tower 100m high casts a shadow of 120 meter long?

*asked by fakku on May 18, 2011* -
## Trigonometry

Sarah used her calculator to find sin125 degree. She wrote down sin125 degrees = -.57. How could Sarah recognize that her answer is incorrect?

*asked by O on March 1, 2015* -
## Trigonometry

over which of the following domains is f(x) = csc(0.1x + 1.2) defined at all points and invertible? x = [0,10] x = [10,20] x = [20,30] x = [30,40] Can someone please explain how to solve this to me and show me all the steps rather than simply giving me the

*asked by Nina on April 19, 2017* -
## Trigonometry

A painter wants to lean a 30-foot ladder against a wall. Safety guidelines recommend that the distance between the base of the ladder and the wall should be 1/4 of the length of the ladder. To the nearest degree, what acute angle should the ladder make

*asked by Mariah on September 30, 2014* -
## TRIGONOMETRY

Use the dot product to determine which of the following vector pairs are orthogonal. a. v1 = (-5,5) and v2 = (1,1) b. v1 = (154,169.4) and v2 = (88,64)

*asked by Kate on May 18, 2013* -
## TRIGONOMETRY

Can you please help me with this question on my study guide for my trig final? Thanks! I'd also appreciate if you can check out my other postings and check my work for some other study guide questions. I want to make sure I'm ready for my final. :) 4.

*asked by Kate on May 16, 2013* -
## trigonometry

Find the exact value of sin(285∘)

*asked by Dan on May 17, 2015* -
## trigonometry

is the value 3pi/2 is a solution for the equation 2sin^2x-sinx-1=0

*asked by Dakeva on August 4, 2011* -
## Trigonometry

The wheels of a scooter have a diameter of 4.5 inches. If the person riding the scooter is traveling down hill at 15.0 mph. what is the approximate angular speed of the wheels in radians per second

*asked by Bob on September 25, 2014* -
## trigonometry

An airplane is flying at an elevation of 5150 ft, directly above a straight highway. Two motorists are driving cars on the highway on opposite sides of the plane, and the angle of depression to one car is 35° and to the other is 55°. How far apart are

*asked by heather on December 2, 2012* -
## Trigonometry

Solve the equation for solutions in the interval 0

*asked by Renee on March 7, 2016* -
## Trigonometry

The Leaning Tower of Pisa in Italy leans because it was built on unstable soil—a mixture of clay, sand, and water. The tower is approximately 58.36 meters tall from its foundation (see figure). The top of the tower leans about 5.45 meters off center. Use

*asked by Kasia on April 23, 2014* -
## Trigonometry

Height of a Kite A 100-foot line is attached to a kite. When the kite has pulled the line taut, the angle of elevation to the kite is approximately 50°. Now everybody lets approximate the height of the kite!

*asked by AwesomeGuy on February 4, 2013* -
## trigonometry

A plane starts from point P and flies 240km on a bearing of 120 degrees to Q. At Q the plane makes a 90 degree turn and flies 100km on a bearing of 210 degrees to R. At R the plane again changes directions and flies back to P.

*asked by bob on September 26, 2018*