Friday

May 6, 2016
**trig, precalc, math, algebra, trigonometry **

Rewrite: tan(cos^−1 (v)) as an algebraic expression in v. Please help me understand.
*Thursday, May 5, 2016 by Veronica *

**trig**

sin 25° cos 35° + cos 25° sin 35°
*Wednesday, May 4, 2016 by EBB*

**Trig**

find the equation for the cosine function that has an amplitude of 3/5, a period of 3pi/2 and a y-intercept of 5.
*Tuesday, May 3, 2016 by Jon*

**Math -Trig**

Determine the exact value if cot(3pi/4) using special triangles. I dont understand how it could be 1/tan3pi/4 in a triangle....
*Tuesday, May 3, 2016 by Jen*

**Math - Trig**

if the diameter of a tire is 3.5 m and makes one rotation every 5 seconds, how far does the tire rotates in one minute?
*Tuesday, May 3, 2016 by Jen*

**Geometry/Trig**

In triangle ABC, A is a right angle, and m b=45 degrees. What is the length of BC? If your answer is not an integer, leave it in simplest radical form. a. 16 ft b. 16 sq 2 ft c. 16 sq 3 ft d. 32 ft I'm really confused as to how to do this... Could someone please explain ...
*Tuesday, May 3, 2016 by Gina*

**trig**

tan(theta)/tan(2theta)-tan(theta)= cos(2theta)
*Sunday, May 1, 2016 by aaron*

**Trig**

Problem: A cable from the top of a 60 foot high tower is to be attached to the ground (x) feet from the base of the tower. A) if the cable makes an angle of t radians with the ground when attached, express t as a function of x. B) if t = pi/5, how far is the end of the cable ...
*Sunday, May 1, 2016 by Chris*

**Trig**

Solve each equation for exact solutions over the interval [0,360)where appropriate. Round approximate solutions to the nearest tenth degree. Sin^2Theta=Cos^2Theta+1 My Work: Using double angle Identity I subtract 1 to other side therefore: 1-Sin^2theta=Cos^2theta= Cos2theta=...
*Wednesday, April 27, 2016 by Ronald*

**Trig**

While fishing on a lake, the fisherman looks up at a cliff. His boat is 23 ft from the base of the cliff, and the angle of elevation is 40 degrees. Find the height of the cliff to the nearest tenth of a foot.
*Wednesday, April 27, 2016 by Tg*

**trig**

A car is traveling at 34 miles per hour. If its tires have a diameter of 14 inches, how fast are the car’s tires turning? Express the answer in revolutions per minute and round to two decimal places.
*Tuesday, April 26, 2016 by EBB*

**trig**

A car is traveling at 34 miles per hour. If its tires have a diameter of 14 inches, how fast are the car’s tires turning? Express the answer in revolutions per minute and round to two decimal places.
*Tuesday, April 26, 2016 by EBB*

**Trig**

Days 0 2 4 6 8 10 12 14 16 Lions (number) 1272 1523 1152 891 1284 1543 1128 917 1185 Deer (number) 39 47 63 54 37 48 60 46 40 Find a sin Equation for Lions and deer. use this model. Thanks! y=k + A sin (Bx+C)
*Monday, April 25, 2016 by Joshaw*

**trig**

Solve triangle ABC. (If an answer does not exist, enter DNE. Round your answers to one decimal place.) a = 63, c = 50, ∠C = 53°
*Tuesday, April 19, 2016 by jorge*

**Math-Trig**

Answer to four significant figures, or to the nearest minute. f) one vertex angle of a rhombus is 25°. Find the ratio of the diagonals.
*Monday, April 18, 2016 by Jessica*

**Trig**

A small plane takes off from island A and flies in a straight line for 12 kilometers. At the same time, a sailor sitting in a sailboat who is 5 miles from the island measures the angled by from island A to the sailboat and the plane is 37 degrees. How far is the plane from ...
*Monday, April 18, 2016 by bobpursley please help*

**Trig**

A Flagpole casts a 60 foot long shadow on the ground. The angle from the tip of the flagpole to the end of the flagpole's shadow measures 35 degrees. How tall is the flagpole? can i use tan(35degrees) = 60/h which gives me 85.714. Please check. Thanks!
*Monday, April 18, 2016 by Steve please check*

**Trig(Check the answer)**

A Flagpole casts a 60 foot long shadow on the ground. The angle from the tip of the flagpole to the end of the flagpole's shadow measures 35 degrees. How tall is the flagpole? can i use cos(55degrees) = 60/h which gives me 104.61. Please check. Thanks!
*Monday, April 18, 2016 by Check*

**Trig**

A Flagpole casts a 60 foot long shadow on the ground. The angle from the tip of the flagpole to the end of the flagpole's shadow measures 35 degrees. How tall is the flagpole? Draw a picture and label. Thank you.
*Monday, April 18, 2016 by Ram*

**Math Trig **

use a double-angle formula to find the exact value of cos2u when sinu=5/13 , where pi/2<u<pi So far I went cos2u=1-sin^2 =1-2(25/169) =1-(50/169)
*Thursday, April 14, 2016 by Larry*

**Trig**

If the terminal side of an angle theta contains the point (-1,3), find secant theta.
*Wednesday, April 13, 2016 by Maxine*

**Trig**

Find sin(x+y), cos(x-y), tan(x+y), and the quadrant of (x+y) if sinx= -1/4, cosy= -4/5, with x and y in quadrant 3.
*Sunday, April 10, 2016 by Brendan*

**trig**

The minute hand of a clock is 7 inches long and moves from 12 to 11 o'clock. How far does the tip of the minute hand move? Express your answer in terms of pi and then round to two decimal places.
*Friday, April 8, 2016 by sareen*

**Trig**

Find the length of a chord intercepted by a central angle of 25 degrees in a circle of radius 30 feet
*Wednesday, April 6, 2016 by Anonymous*

**trig**

2(sinx)^2-5cosx-4=0 Solve for all solutions between [0,2pi]
*Tuesday, April 5, 2016 by Anonymous*

**Trig**

suppose that the angle theta is in the second quadrant, and that sin(theta)=1/3. Find exact values for cos (theta) and csc (theta)
*Tuesday, April 5, 2016 by alicia otto*

**Grade 11 Math Trig Ratio**

Solve cos315*cos(-390)-sin225*sin750 cos315: <RA = 360-315 = 45 cos45 = 1/√2 cos-390: <RA=-390+360 =30 cos30= √3/2 sin225: <RA = 225-180 = 45 Sin45=1/√2 Sin750: <RA = 750 - 2(360) =30 Sin30=1/2 Put it all together... (1/√2)(√3/2)-(1/&#...
*Tuesday, April 5, 2016 by AmbiguousCase*

**Trig**

How do I write cos(11x)cos(x)+sin(11x)sin(x) as a single trigonometric function? Please show steps.
*Sunday, April 3, 2016 by Anonymous*

**trig**

Angle θ lies in the second quadrant, and sin θ = 3/5. Find cos θ and tan θ.
*Friday, April 1, 2016 by Britt*

**Trig**

Find the exact values of sec(x)=7. I know that cos(x)=1/7. I know that sin(x)= sqrt(1-91/4900). I know that tan(x)=1. I know how to do the problem but I'm not really sure why, and I'd like to know. I got 4sqrt(3). Please help!
*Friday, April 1, 2016 by Emily*

**trig**

Which expression is equivalent to tan(-x)cos^2x? -sin xcos x sin xcos x tan x + sin2x tan x − sin2x -tan x − sin2x
*Thursday, March 31, 2016 by jimmy*

**Trig**

If tan A= 3/4 and cos B=-5/13, where A and B are both third-quadrant angles, find sin(A+B). Please explain how you found all the answers
*Thursday, March 31, 2016 by Lexi*

**geometry and trig**

I have a regular octagon with a radius of 9. I have split the 8 pie slices into right angles--leaving angles 90, 67.5, and 22.5. I looked for the sine of 22.5 opp/hyp and get .38. Then the oppositeside is 6.84. I can't get the right answer, what am I doing wrong? Thanks
*Wednesday, March 30, 2016 by lulu*

**Trig Help**

Given the equation for simple harmonic method d=1.3cos(3pi/4 t) answer the following questions: a)Find the maximum displacement. 1.i got 1.3 b)Find the frequency and length of the pendulum c)Calculate the value of d when t=3 i got .919 d)Determine the least positive value of t...
*Thursday, March 24, 2016 by Ryan*

**Trig**

Find the algebraic expression that is equal to sec theta - cos (-theta)
*Thursday, March 24, 2016 by Amanda*

**Trig**

find the algebraic expression that is equal to sin (-theta) sec(-theta) cot(-theta)
*Thursday, March 24, 2016 by Amanda*

**trig**

Simplify and write the trigonometric expression in terms of sine and cosine: cot(-x)cos(-x)+sin(-x)=-1/f(x)=f(x)=____________ I've tried everything, I think that the "-1/f(x)" part is screwing up my answer but I'm not sure what it's asking me to do...
*Wednesday, March 23, 2016 by mv*

**trig**

a building 60 feet high. from a distance at point A on the ground, the angle of elevation to the top of the building is 40 degree. from a little nearer at point B, the angle of elevation to the top of the building is 70 degree. What's the distance between point A and B ?
*Friday, March 18, 2016 by Anonymous*

**Trig identity.**

I need help with verifying these trig identities: 1) sin4x = 4sinxcos - 8sin^3 x cos x 2) cos3x = cos^3 x - 3sin^2 x cos x
*Tuesday, March 15, 2016 by Jane*

**Trig help**

Can someone help me find ALL solutions in the interval [0,2π) for the given equations. Please show work. 1) sin2x = sin2x 2) tan2x +tanx = 0
*Tuesday, March 15, 2016 by Jane*

**Trig**

I have a diagram of how far a discus was thrown. From A to B is 100m, C is perpendicular to A, from A to C is 50m, A and B are connected to D (it should be a triangle), A has a 40° angle and B has a 75° angle. C is not perpendicular to D btw.. a. Find AD and use it to ...
*Sunday, March 13, 2016 by Anonymous*

**Trig**

The original screamer radius =100 feet rotated 1 deg per sec. The engg decided to make it scarier by making it rotate 18 deg per second. Write the new equation for the vertical position of a passenger on the screamer where the domain is now the time per revolution (in sec)
*Thursday, March 10, 2016 by skk*

**Trig - Ambiguous Cases**

Triangle HAV has <H = 124, a=8.5mm, and h=7.2mm How many solutions are there? What I attempted: SinH/h=SinA/a Sin124/7.2=SinA/8.5 SinA=8.5(Sin124/7.2) <A = 78.2 RULE => All interior angles must add up to 180 degrees therefore this triangle has 0 solutions. The ...
*Wednesday, March 9, 2016 by AlphaPrimes*

**trig**

half angle formula to find exact value cos 112.5 degree
*Tuesday, March 8, 2016 by Billy*

**trig**

sin^4x
*Tuesday, March 8, 2016 by Billy*

**trig**

sin 2x-cot x=
*Tuesday, March 8, 2016 by Billy*

**trig **

Find all solutions in the interval [0,2π) for cos(x - π/6) = 1 + cos(x + π/6). Show work, please and state in solution set.
*Tuesday, March 8, 2016 by Jane*

**Trig please**

The height h in inches of pistons 1 and 2 in an automobile engine can be modeled by h1 = 3.75sin(733t) + 7.5 and h2 = 3.75sin[733(t+ 4π/3)] + 7.5 where t is measured in seconds. How often are these two pistons at the same height? Show work please.
*Tuesday, March 8, 2016 by Jane*

**Trig**

Given sin= -√5/6 with π < u < 3π/2 and cos v= √3/5 with 0 < v < π/2 find sin(u-v) and tan(u+v). Please show work and simplify.
*Tuesday, March 8, 2016 by Jane*

**Trig sum please help**

Write the augmented matrix, and then solve the system, using Gauss Jordan elimination on the augmented matrix. x + 2y - z = 4 -2x + y - 4z = -6 4x - 3y + 2z = -10
*Monday, March 7, 2016 by Crystal*

**trig**

Solve for sin4x=sin2x?
*Monday, March 7, 2016 by Anonymous*

**trig plz help**

Solve. Round off your answer to the nearest foot. (The picture is not drawn to scale.) A balloon is 1500 feet above the ground. The angle of depression from the balloon to headquarters is 46°21'. How far is the headquarters from a point on the ground directly below the...
*Sunday, March 6, 2016 by ashley*

**trig**

Find the exact values requested. No decimal approximations. Given that cot θ = 4 for an acute angle θ, A. Find sinθ. B. Find cos(2θ).
*Sunday, March 6, 2016 by brittney*

**trig**

verify (csc^4-1)/cot^2x=2+cot^2x So this is what I have so far on the left side (csc^2x+1)(cscx+1)(cscx-1)/cot^2x =(csc^2x+1)(cot^2x)/cot^2x i think I'm doing something wrong. Please help!
*Sunday, March 6, 2016 by Diana*

**trig plz help**

Solve, finding all solutions in the interval [0, 2π). tan(3x) = -1
*Sunday, March 6, 2016 by brittney*

**trig gauss jordan**

Write the augmented matrix, and then solve the system, using Gauss Jordan elimination on the augmented matrix. x + 2y - z = 4 -2x + y - 4z = -6 4x - 3y + 2z = -10
*Sunday, March 6, 2016 by shawn*

**trig help**

Find the equation of the hyperbola satisfying the given conditions. Vertices at (5, 1) and (-7, 1); asymptotes (y - 1) = 1/3(x + 1) and (y - 1) = -1/3(x + 1)
*Sunday, March 6, 2016 by shawn*

**last 2 questions trig!!**

4. Solve the triangle(s), if possible. Round to the nearest tenth. Solve the triangle. Side a = 8, side b = 10, side c = 12 6. Two boats leave the same dock at the same time. The first sails in a straight line N40°W at 36 miles per hour and the second goes in a straight ...
*Sunday, March 6, 2016 by ashley*

**math 108 trig **

1.Solve, finding all solutions in [0, 2π). cosx sin2x + sinx cosx - sinx = 0 2.Solve, finding all solutions in [0, 2π). 3sec x = 2tan^2x
*Sunday, March 6, 2016 by brittney*

**plz help trig!!!!!**

A boat sails 20 km in a direction of N75°E. Draw the 20 km travelled in a direction of N75°E as a vector v in standard position. Find the component form of the vector v. Round your answers to the nearest hundredth. 2 pts. B. Next, the boat turns and sails 10 km in a ...
*Sunday, March 6, 2016 by ashley*

**trig plz help**

A boat sails 20 km in a direction of N75°E. Draw the 20 km travelled in a direction of N75°E as a vector v in standard position. Find the component form of the vector v. Round your answers to the nearest hundredth.
*Sunday, March 6, 2016 by jre*

**trig exact vales**

Find the exact values requested. No decimal approximations. Given that cot θ = 4 for an acute angle θ, A. Find sinθ. B. Find cos(2θ).
*Sunday, March 6, 2016 by jre*

**trig/ellipse equation**

Find an equation of an ellipse satisfying the given conditions: Vertices: (-1, -8) and (-1, 4); and the length of the minor axis is 10.
*Sunday, March 6, 2016 by jre*

**Calculus**

Integrate dx/(sqrt(x^2+16)). I have no idea how to start and which method to use. Thinking some sort of trig substitution? But it doesn't look like it. Step by step? Answer key says ln|x+ sqrt(x^2+16)|.
*Saturday, March 5, 2016 by Cindy*

**Trig**

Solve for [0,2pi) 2cos4x + sqrt3 = 0
*Friday, March 4, 2016 by Anonymous*

**trig**

A wheel with a 22 inch diameter is turning at the rate of 31 revolutions per minute. What is the linear speed of a point on the rim, measured to the nearest inch per minute?
*Friday, March 4, 2016 by jre*

**trig**

From a boat on the bay, the angle of elevation to the top of a cliff is 29°10’. If the bottom of the cliff is 1860 feet from the boat, how high is the cliff (to the nearest foot)? Assume that a right triangle is formed.
*Friday, March 4, 2016 by jre*

**Trig application**

A man is holding a gun 4 feet above the ground and fires into an open field. The bullet has an initial velocity of 300 feet per second and an initial angle of 30°. Find the range (the horizontal distance traveled before hitting the ground ) and the bullet's max height...
*Friday, March 4, 2016 by Jane*

**Trig application**

I'm having trouble with this trig application. The scenario goes: A ferris wheel has a diameter of approximately 65 meters. Assume it takes 110 seconds for the ferris wheel to make one complete rotation. find the angular speed of the ferris wheel in radians per minute and ...
*Thursday, March 3, 2016 by Jane*

**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.)
*Wednesday, March 2, 2016 by Courtney*

**trig**

A ship is passing through the island of corregidor. at its closest point of approach, Corregidor radar determines that it is 2, 400 meters away. Later, the radar determines that it is 2, 650 meters away. a.) By what angle did the ship's bearing from corregidor change? b.) ...
*Tuesday, March 1, 2016 by Alle*

**Trig**

Find the arc length of a circle that has a central angle of 270 degrees and a radius of 10 yards.
*Monday, February 29, 2016 by Hrc*

**Trig**

The Stratosphere Tower is Las Vega dominate the city's landscape by rising 1,149 feet above the desert floor. The restaurant at the top of the tower turns slowly and completes a full revolution in one hour. How many radians will the restaurant have rotated in 52 minutes?
*Monday, February 22, 2016 by Lux*

**Trig Identities**

Why does cos^2(x)= 1/2cos(2x)+1/2? I am trying to integrate, but the answer key says to first rewrite the expression like the above. I don't get how to change cos^2(x) into that. Explain?
*Sunday, February 21, 2016 by Betty*

**Trig**

a road is inclined at an angle of 45degrees. After driving 300 feet along this road, find the driver's increase in altitude.
*Friday, February 19, 2016 by Scott*

**Trig**

a 12-ft-long guy wire is attached to a telephone pole 10.5 ft from the too of the pole. If the water forms a 52 degree angle with the ground, how high is the telephone pole?
*Wednesday, February 17, 2016 by Dave*

**Trig application**

Can anyone help me with this problem? I'm so confused. Please help. A security camera is placed 27 feet from the counter at a store. The counter is 18 feet long and the camera is placed 4 feet from one end. What angle, to the nearest degree, should the camera rotate ...
*Tuesday, February 16, 2016 by Jane*

**Trig identity inverses**

Find the exact value of cos[cot^-1 (-√3) + sin^-1 (-1/2)]. I'm having trouble with inverses. Please help by showing work.
*Tuesday, February 16, 2016 by Jane*

**Trig**

Find the exact value of csc 4pi/3 What I have determined thus far: 4pi/3 = 60 degrees sin = square root of 3/2
*Saturday, February 13, 2016 by Lara*

**Trig.**

If TanTheta= -65/72 and the terminal side of theta lies in Quadrant II use a pythagorean identity to find sec theta.
*Saturday, February 13, 2016 by Joe*

**Trig**

Find all values of theta where 0degrees<theta<360 degrees when csc theta = square root 2 Please detail how/why i can get to the solution. I need to understand the concept clearly...... It will probably relate to something taught down the line I'm sure.
*Saturday, February 13, 2016 by Lara*

**Trig**

Find all values of theta where 0degrees<theta<360 degrees when csc theta = square root 2
*Saturday, February 13, 2016 by Lara*

**Trig**

Find all values of theta where 0degrees<theta<360 degrees when csc theta = square root 2
*Saturday, February 13, 2016 by Lara*

**Trig**

If cot theta = -12/5 and the terminal side of theta lies in quadrant II find secant theta
*Saturday, February 13, 2016 by Lara*

** trigonometry (Trig Equation)**

sin 3x=-1
*Friday, February 12, 2016 by alex*

**trigonometry (Trig Equation)**

4 cos 2x + 3 cos x = 1
*Thursday, February 11, 2016 by alex*

**Trig**

If tan theta = a/b, where a and b are positive, and if theta lies in quadrant III, find sin theta
*Friday, January 29, 2016 by Eka*

**Trig**

The Leaning Tower of Pisa is 55m tall. The tope edge of the tower is 5m out from the bottom edge. What is the angle created between the ground and the tower? Round your answer to the nearest degree. tan -1 (55/5) = 85 degrees but my Brother says I did it wrong that the angle ...
*Friday, January 29, 2016 by Ron*

**Purdue Trig**

A spherical balloon is being inflated so that radius is increasing at a rate of 10 mm/sec.
*Thursday, January 28, 2016 by Dave Thompson*

**Please help me with trig.**

One more problem.. Given sin t= 3/11 and cos t<0, find the values of the remaining 6 trig functions.
*Wednesday, January 27, 2016 by Jane*

**Please help me with Trig**

Given cos 67.5° = [√(2+√2)]/2, find tan 67.5° , simplify where needed, and show work. I'm starting to learn this stuff, and I'm so confused where to start. I know they gave me the coordinate X as in cos 67.5° = [√(2+√2)]/2, and I ...
*Wednesday, January 27, 2016 by Jane*

**Functions & Trig**

evaluate each function at the given value: f(n)=-n^6+31n^4+26n^3+20n^2+-33n-20 when n=6 I was thinking that I should do synthetic division, but I've tried it a few times and I can't get it to work out correctly. Please help!
*Tuesday, January 26, 2016 by Kerry*

**Functions & Trig**

evaluate each function at the given value: f(n)=-n^6+31n^4+26n^3+20n^2+-33n-20 when n=6 I was thinking that I should do synthetic division, but I've tried it a few times and I can't get it to work out correctly. Please help!
*Tuesday, January 26, 2016 by Kerry*

**trig**

Two ships leave port at the same time and travel straight line distances, the first at 30 km/h and the second at 10 km/h. Two hours later they are 50 km apart. What is the angle between their courses?
*Sunday, January 24, 2016 by owen*

**trig**

In a certain right triangle, the two sides that are perpendicular to each other have lengths h = 4.40 m and b = 8.70 m. What is the length of the third side of the triangle?
*Saturday, January 23, 2016 by jojo*

**Calculus**

Use the identity sin^2x+cos^2x=1 and the fact that sin^2x and cos^2x are mirror images in [0,pi/2], evaluate the integral from (0-pi/2) of sin^2xdx. I know how to calculate the integral using another trig identity, but I'm confused about how to solve this one.
*Tuesday, January 19, 2016 by Rostrastics*

**Trig**

Distance between the goal posts, 19.5 feet, is the length of an arc on a circle of radius 50 yards. The kicker aims to kick the ball midway between the uprights. To score a field goal, what is the maximum number of degrees that the actual trajectory can deviate from the ...
*Tuesday, January 19, 2016 by moscato*

**Calculus**

Use the identity sin^2x+cos^2x=1 and the fact that sin^2x and cos^2x are mirror images in [0,pi/2], evaluate the integral from (0-pi/2) of sin^2xdx. I know how to calculate the integral using another trig identity, but I'm confused about how to solve this one.
*Monday, January 18, 2016 by Andre*

**Trig**

An air traffic controller tells the pilot of an airplane flying due east to turn the plane so that it has a heading of 120 degrees east of north. What angle does the airplane turn and which direction is the plane now headed?
*Wednesday, January 13, 2016 by Kiana *

**Trig - 9th grade**

Can you help me solve: 5sin2x + 3sinx - 1 = 0 Thanks
*Sunday, January 10, 2016 by Carol*