# trigonometry

Popular questions
1. ## Trigonometry

Let (7,-3) be a point on the terminal side of theta. Find the exact values of cos of theta, sec of theta and cot of theta?

asked by Anna on March 20, 2014
2. ## Trigonometry

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

asked by Kewal on February 10, 2012
3. ## 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
4. ## 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
5. ## 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
6. ## trigonometry

Find the values of s in the interval [0,pi/2] that make the statements true. 1. sin s=0.75438373 2. cos s=0.74241049 3. cot s=5.6394377 Can you tell me how you solve these.

asked by y912f on January 7, 2009
7. ## 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
8. ## Trigonometry

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

asked by Kewal on January 9, 2012
9. ## 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
10. ## 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
11. ## 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
12. ## trigonometry

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

13. ## TRIGONOMETRY

Express tan theta in terms of cosec theta

asked by MaThS on March 26, 2016
14. ## 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
15. ## Trigonometry

Three ships are situated as follows: A is 225 miles west of C while B, due south of C, bears S25*10'E from A. a. How far is B from A? b. How far is B from C? c. what is the bearing of A from B? PLEASE EXPLAIN

asked by Roy on September 9, 2012
16. ## Trigonometry

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

asked by ALISON on October 23, 2011
17. ## 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
18. ## Trigonometry

Two ships leave a harbor entrance at the same time. The first ship is traveling at a constant 10 miles per hour, while the second is traveling at a constant 22 miles per hour. If the angle between their courses is 100°, how far apart are they after 2

asked by Alice on July 30, 2015
19. ## 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
20. ## Trigonometry

find sin2x, cos2x, and tan2x if sinx= -2/sqrt 5 and x terminates in quadrant III

asked by Elena on March 25, 2014
21. ## Trigonometry

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

asked by Katie on April 4, 2016
22. ## Trigonometry

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

asked by Kewal on December 31, 2011
23. ## trigonometry

can you please tell me what is the sec of (-855 degrees). and how to find it. thnks

asked by y912f on January 7, 2009
24. ## Trigonometry

If the radius of a pizza is 20 cm, what is the central angle in degrees that gives one person 30 cm of crust? Question 5 options: a) 120° b) 35° c) 43° d) 86° I say option a, but my partner disagrees

asked by Muneer on June 18, 2020
25. ## Trigonometry

Mike's hot-air balloon is 875.0 m directly above a highway. When he is looking west, the angle of depression to Exit 81 is 11 °. The exit numbers on this highway represent the number of kilometers left before the highway ends. What is the angle of

asked by Krystle on June 15, 2020
26. ## Trigonometry

Find all solutions of the equation in the interval [0,2pi). sec(theta)+2=0 Write your answer in radians in terms of pi

asked by Pascal on March 25, 2014
27. ## Trigonometry

which of the following is a solution for the equation 1/485 tan^2x=0 a) no solution b) 485 pi c) pi d) pi/2 I'm getting conflicting answers when I try to solve it.

asked by Muneer on June 18, 2020
28. ## 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
29. ## 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
30. ## 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
31. ## 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
32. ## Trigonometry

Hi! I was unsure of how to answer this question.....could i get some help? Two angles of a triangle are 25 degrees and 40 degrees and the shortest side is 20 cm. Find the length of the longest side

asked by Cassandra on June 15, 2020
33. ## Trigonometry

a 30 feet ladder resting against a building makes a 60 angle with the ground . find the Height from the ground at which the ladder touches the building to the nearest foot

asked by :) on March 5, 2012
34. ## Trigonometry

Find all solutions of the equation in the interval [0, 2π). (Enter your answers as a comma-separated list.) cos(x+3pi/4) - cos(x-3pi/4) = 1

asked by Thomas on March 1, 2019
35. ## 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
36. ## 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
37. ## Trigonometry

4. Find the exact value for sin(x+y) if sinx=-4/5 and cos y = 15/17. Angles x and y are in the fourth quadrant. 5. Find the exact value for cos 165degrees using the half-angle identity. 1. Solve: 2 cos^2x - 3 cosx + 1 = 0 for 0 less than or equal to x

asked by Tiffany Enlow on April 10, 2009
38. ## Trigonometry

A bridge across a valley is 150 m in length. The valley walls make angles of 60° and 54° with the bridge that spans it, as shown. How deep is the valley, to the nearest metre?

asked by Dylan on June 13, 2019
39. ## Trigonometry

If a point on the Cartesian plane lies at (4, 2), what is the angle made between the line containing the point and the origin, and the negative y-axis? a) 1.249 radians b) 0.463 radians c) 0.523 radians d) 1.047 radians

asked by Jeff on June 18, 2020
40. ## 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
41. ## trigonometry

A 3m high fence is on the side of a hill and tends to lean over. The hill is inclined at an angle of 20 degree to the horizontal. A 6.3 m brace is to be installed to prop up the fence. It will attached to the fence at a height of 2.5 m and will be staked

asked by Krystle on June 14, 2020
42. ## trigonometry

Rewrite 4sin(x)-5cos(x) as Asin(x+phi)

asked by Anonymous on May 7, 2017
43. ## Trigonometry

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

asked by Rene on April 5, 2013
44. ## 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
45. ## 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
46. ## 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
47. ## 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
48. ## Trigonometry

Which interval gives an average change of 0 for the function y = 3cos (4πx + π) - 3? a) π/3

asked by Craig on June 18, 2020
49. ## Trigonometry

At t = 0 a car is due 2 km north of you heading west moving 13 km/s after 1.5 s. What is the angle in radians between you and the car from where the car was at t = 0?

asked by Muneer on June 18, 2020
50. ## Trigonometry

Evaluate the expression: 1) 1 - 2sin^2 π/2

asked by Muneer on June 18, 2020
51. ## Trigonometry

A 19-ft ladder leans against a building so that the angle between the ground and the ladder is 80∘. How high does the ladder reach on the building? I did 19sin(80) to get me 18.76847847 for how high the ladder reach on the building... but when i put the

asked by Michael on April 20, 2015
52. ## Trigonometry

Prove that tan2A = (sec2A+1)√sec²A-1

asked by Kewal on January 6, 2012
53. ## Trigonometry

The angle of elevation from a point on the ground to the top of a pyramid is 23^•(degree)40^’(minutes). The angle of elevation from a point 112 ft farther back to the top of the pyramid is 15^•30’. Find the height of the pyramid.

asked by Vin on June 25, 2020
54. ## Trigonometry

If the central angle is 4pi/3 radians, what should the radius of a circle be to make the arc length 1 m? a) 0.424 m b) 0.238 m c) 2.356 m d) 4.188 m I think it is c)... is that correct?

asked by Jeff on June 18, 2020
55. ## Trigonometry

If k = 2π/45, what is the period?

asked by Muneer on June 18, 2020
56. ## Trigonometry

Evaluate each expression: a) ( tan π/12 + tan 7π/4 ) / ( 1 - tan π/12 x tan 7π/4) b) cos π/4 cos π/12 + sin π/4 x sin π/12 c) sin 7π/5 cos π/15 - cos 7π/5 sin π/15

asked by Muneer on June 18, 2020
57. ## 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
58. ## 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
59. ## Trigonometry

Solve the following Trigonometric equations, where 0

asked by Muneer on June 18, 2020
60. ## Trigonometry

Find all degree solutions. (Enter your answers as a comma-separated list. Let k be any integer.) 2 cos2 6θ + 3 cos 6θ + 1 = 0

asked by gail on April 7, 2018
61. ## Trigonometry

This is a logs question If u=x/y^2, which expression is equivalent to log u? 1) log x + 2 log y 2) 2(log x- log y) 3) 2(log x + log y) 4) log x- 2 log y

asked by Charles on February 11, 2012
62. ## Trigonometry

cos2Acos2B + sin²(A-B) - sin²(A+B) = cos(2A+2B)

asked by Kewal on January 12, 2012
63. ## 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
64. ## trigonometry

if sin2x=3sin2y, prove that: 2tan(x-y)=tan(x+y) ( here, in sin2x, 2x is an angle., like there's a formula:sin2x=2sinxcosx and sin2y=2sinycosy; ....)

asked by aayush on January 25, 2008
65. ## Trigonometry

Given sin x=5/13 and 0

asked by Muneer on June 18, 2020
66. ## 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
67. ## 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
68. ## Trigonometry

change 8 cis 240 degrees to rectangular form

asked by steve on December 9, 2013
69. ## Trigonometry

Evaluate Each Expression: a) 2cos^2 2π/3 - 1 b) cos^2 7π/8 - sin^2 7π/8 c)2sin 11π/12 x cos 11π/12 d) 1 - 2sin^2 π/2

asked by Muneer on June 10, 2020
70. ## trigonometry

Find all solutions 4sin^(2)x - 4sin(x) + 1 = 0

asked by rainbow on April 1, 2020
71. ## 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
72. ## trigonometry

Solve the following equation for all solutions: sin(6x)cos(11x)-cos(6x)sin(11x)=-.1

asked by Dan on May 15, 2015
73. ## Trigonometry

If cospΘ + cosqΘ = o. prove that the different values of Θ form two arithmetical progressions in which the common differences are 2π/p+q and 2π/p-q respectively.

asked by Kewal on December 23, 2011
74. ## 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
75. ## Trigonometry

Find the diameter of a pulley which is driven at 360 rpm by a belt moving at 40 ft/s. Then in 1 s the pulley turns through an angle theta measuring 12 pi radians and a point on the rim travels a distance s= 40 ft.

asked by Geee on November 10, 2017
76. ## 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
77. ## Trigonometry

An airplane is sighted at the same time by two ground observers who are 2 miles apart and both directly west of the airplane. They report the angles of elevation as 11˚ and 20˚. How high is the airplane? Round to the nearest hundredth of a mile.

asked by Remy on August 5, 2015
78. ## 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
79. ## Trigonometry

The expression log(x^n/ radical y)is equivalent to 1. n log x - 1/2 log y 2. n log x- 2 log y 3. log (nx) - log (1/2y) 4. log (nx) - log (2y)

asked by Stephen on February 11, 2012
80. ## Trigonometry

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

asked by Michael on June 5, 2010
81. ## Trigonometry

Angle x is a third quadrant angle such that cos x = -(2/3). What is the exact value of cos (x/2) ? Solve in simplest radical form.

asked by Kayla on March 5, 2020
82. ## 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
83. ## Trigonometry

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

asked by Xiumin on October 30, 2014
84. ## 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
85. ## Trigonometry

cos²a + cos²(a+120°) + cos(a-120°) = 3/2

asked by Kewal on January 12, 2012
86. ## 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
87. ## trigonometry

From the top of a fire tower, a forest ranger sees his partner on the ground at an angle of depression of 40º. If the tower is 45 feet in height, how far is the partner from the base of the tower, to the nearest tenth of a foot? (Detailed explanation

asked by Saif on June 3, 2020
88. ## Trigonometry

Find the value of x. Round to the nearest tenth. The diagram is not drawn to scale. The adjacent is 12cm wide and the angle of the hypotenuse is at 35 degrees. The opposite is x. I'm posting this here because I want to know what I did wrong regarding my

asked by A Victim of Bullying on April 10, 2020
89. ## Trigonometry

Write the expression as a trigonometric function of only θ, and use a graphing utility to confirm your answer graphically. cos((9π/2)-θ

asked by Thomas on March 1, 2019
90. ## trigonometry

a triangle has sides equal to 68 cm, 77 cm and 75 cm, respectively. find the area of the escribed circle tangent to the shortest side of the triangle.

asked by jack on June 17, 2017
91. ## 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
92. ## trigonometry

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

asked by clive on May 5, 2015
93. ## 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
94. ## Trigonometry

Calculate the area: From a point A, proceed east for 300 m to Point B. Then travel 420 m on a bearing S35°E to point C. Then travel along a bearing of S40°W for 500 m to Point D. Then return to Point A.

asked by Lulu on July 21, 2012
95. ## trigonometry

From a mountain 1780 ft. high, the angle of depression of a point on the nearer shore of a river is 48deg40mins and of point directly across on the opposite side is 22deg20mins. What is the width of the river between the two points?

asked by Winsel on August 10, 2010
96. ## Trigonometry

An elliptical arch is constructed which is 6 feet wide at the base and 9 feet tall in the middle. Find the height of the arch exactly 1 foot in from the base of the arch. looking for direction with what ellipse equation is and how to approach this problem

asked by CodyJinks on June 19, 2019
97. ## Trigonometry

a rope dancer was walking on a loose roop tied to the top of two equal post of height 9m. when he was 3m above the ground, it was found that stretched pieces of roop made angle of 30 degree and 60 degree with the horizontal line parallel to the ground.

asked by Akash on January 23, 2018
98. ## trigonometry

the angle of elevation of a tower at place A south of it is 30degrees and at B west of A and a distance of 50 from it the angle of elevation is 18degrees, determined the height of the tower

asked by jack on June 5, 2017
99. ## Trigonometry

Determine the general solution of Sin2x=4cos2x thanks in advance

asked by alex on October 26, 2015
100. ## Trigonometry

(Triangle ABC is scalene) AC is a straight shore line and B is a boat out at sea. Angle A is 60 degrees and Angle C is 45 degrees. Find the shortest distance from the boat to the shore if A and C are 5km apart...I honestly have no idea where to start with

asked by Abby on January 28, 2015