Find sin2theta, cos2theta, and tan2theta for costheta = -12/13 in pi < theta < 3pi/2. My answers: 20111/24336 for tan2theta. 144/169 for cos2theta -120/338 for sin2theta
Wednesday, May 20, 2015 at 7:38pm
algebra 2 and trig
The scores on a chemistry test are normally distributed. Approximately 95 percent of the scores fell between 78 and 92. What is the standard deviation for this distribution?
Monday, May 18, 2015 at 7:45pm
Solve the equation for the given domain. 4cos^2 θ = 1 for 0 to 360 degrees. I get 60, 120, 240, and 300. Are these correct? If so, how would I represent them with some sort of expression?
Saturday, May 16, 2015 at 6:03pm
Prove the following identities: 13. tan(x) + sec(x) = (cos(x)) / (1-sin(x)) *Sorry for any confusing parenthesis.* My work: I simplified the left side to a. ((sinx) / (cosx)) + (1 / cosx) , then b. (sinx + 1) / cosx = (cos(x)) / (1-sin(x)) I don't know how to verify the ...
Tuesday, May 12, 2015 at 9:09pm
a vertical pole 35 feet high, standing on sloping ground, is braced by a wire which extends from the top of the pole to a point on the ground 25 feet from the foot of the pole. If the pole subtends an angle of 30 degree at the point where the wire reaches the ground, how long ...
Sunday, May 10, 2015 at 2:34am
A ladder 35.4 feet long is leaning against an embarkment inclined 62.5 degrees to the horizontal. If the bottom of the ladder is 10.2 feet from the embarkment, what is the distance from the top of the ladder down the embarkment to the ground?
Sunday, May 10, 2015 at 2:30am
From a certain point, the angle of elevation of the top of the building is 38. From a point 75 feet nearer the building, the angle of elevation is 65. Find the height of the building.
Saturday, May 9, 2015 at 11:22pm
Two pilots take off from the same airport. Mason heads due south. Nancy heads 23 west of south. After 400 land miles, how far is Nancy from Masons route? I think 156.29, but I'm not sure because the question comes in a lesson on sum and difference identities...
Saturday, May 9, 2015 at 8:20pm
Find sin(s+t) and (s-t) if cos(s)= 1/5 and sin(t) = 3/5 and s and t are in quadrant 1. =Sin(s)cos(t) + Cos(s)Sin(t) =Sin(1/5)Cos(3/5) + Cos(-1/5)Sin(3/5) = 0.389418 Sin(s-t) =sin(s)cos(t) - cos(s)sin(t) =sin(-3/5)cos(1/5) - cos(1/5)sin(3/5) =Sin-3/5 cos-3/5 = -0.46602 HELP ...
Thursday, May 7, 2015 at 9:47am
Find the values of sin 0, cos 0, and tan 0áif the angle 0áis in standard position and its terminal side passes through the point (¡V15, 8). Give answers as fractions.
Sunday, May 3, 2015 at 12:28pm
Find the bearing and airspeed for a plane to fly 630 miles due north in 3 hours if the wind is blowing from a direction of 318* and is blowing at 15mph. Approximate the bearing to the nearest degree and the speed to the nearest mile per hour.
Tuesday, April 28, 2015 at 4:37pm
Forces of 15 kg and 10 kg act on a point with an angle of 60◦ between the forces. Find the magnitude of the resultant force (to nearest tenth of a kilogram) and the angle (to the nearest degree) the resultant makes with the 15 kg force
Tuesday, April 28, 2015 at 2:13pm
The equation of a transverse wave traveling in a string is given by y(x,t) = 10 cos (π/2)(0.0050x - 8.0t + 0.57), in which x and y are expressed in centimeters and t in seconds. Write down the equation of a wave which, when added to the given one, would produce standing ...
Tuesday, April 28, 2015 at 4:24am
Please help with this question: A plane travels a distance of 140 km due west of Vancouver International Airport. It then travels 60 km at a bearing of 340 degrees. How far from the Airport is the plane? Thank you for all your help.
Monday, April 20, 2015 at 9:13am
Can you please help with this trig question: The angle of elevation to the top of a nearby mountain is 46 degrees. After walking 1 km toward the mountain, you determine the angle of elevation to be 68 degrees. How high is the mountain? Thank you for all your help.
Monday, April 20, 2015 at 8:43am
Precalculus Trig (Geometry)
A rectangular doorway is 38 meters wide and 60 meters high. The doorway is capped with a semi-ellipse that is 13 meters high at its center. Find the height h of the doorway and window 5 meters from the center. From the ellipse equation, I can see that a should be 19 and b ...
Sunday, April 19, 2015 at 4:55pm
Precalculus Trig (Geometry)
A large doorway has the shape of a parabolic arch. The doorway is 20 feet high at the top of the arch and 20 feet wide at the base. At a height of 10 feet above the floor, find the width of the arch. If you start the vertex of the parabola at 0,0, that means the equation ...
Sunday, April 19, 2015 at 4:49pm
Karen earns 43 dollars per week working pt at a bookstore. she makes one dollar more for each book she sells. the amt A, in dollars that Karen earns in a week ifshe sells b books is given in the function A(b) =43 + b how much does she earnin a week if she sells 22 books?
Saturday, April 18, 2015 at 1:06am
Initially a fifty foot ladder rests against a wall. As I start to climb it, the ladder slides down, finally stopping such that the ladder touches the wall at a point 8 feet below where it originally touched the wall. During the slide, the base of the ladder slid 16 feet from ...
Wednesday, April 15, 2015 at 6:44pm
if sin23=p,write down the following in terms of P *cos113 *cos23 *sin46 so i draw the diagram an solve for x in terms of P an got 1-p so i dont know how to apply cos113and sin46 in terms of 23 or P but *cos 23 i wrote it as> 1-p/1 wch is 1-p
Sunday, April 5, 2015 at 11:46am
Calculus 2 (Differential Equation)
How would you solve the following problem explicitly? Sqrt(1-y^2) dx - sqrt(1-x^2) dy I separated the x and y terms and got: Integral of 1/sqrt(1-x^2) dx = Integral of 1/sqrt(1-y^2) dy I was wondering how would you take the anti-derivative of each function. I believe we are ...
Thursday, March 26, 2015 at 3:40am
calculus trig substitution
∫ x^3 √(x^2+9) dx If you work it can you write the steps? I really don't like the way my teacher teaches it. Someone else doing it might help.
Saturday, March 14, 2015 at 8:39pm
A frisbee is thrown within an angular velocity of 360 rpm. If the diameter of the frisbee is 12 inches, how fast does it travel when it hits the ground rolling on the side? round your answer to the nearest mph
Thursday, March 12, 2015 at 12:36am
Trig verifying identities
I am having trouble with this problem. sec^2(pi/2-x)-1= cot ^2x I got : By cofunction identity sec(90 degrees - x) = csc x secx csc-1 = cot^2x Then split sec x and csc-1 into two fractions and multiplied both numerator and denominators by csc and got: sec x csc^2x-1= cot^2x ...
Monday, March 9, 2015 at 7:07pm
i think its a or b Which scenario describes periodic behavior? A pendulum swinging back and forth A ball bouncing up and down on the ground The takeoff and landing of a jet plane The path a dolphin swims in the ocean
Friday, March 6, 2015 at 1:58pm
Solve tan(40/90) for the double angle cos(2theta). I know I use the x^2 + y^2 = r^2 formula and cos(2theta) = cos^2theta - sin^2theta. But I don't understand my answer
Wednesday, March 4, 2015 at 10:09pm
trig with enough info?
Two oil Wells are 4 km and 6 km from the river. The points along the river are 8 km apart. Find the common loading point on the river, using the shortest amount of pipe.
Wednesday, February 25, 2015 at 6:30pm
An airplane is traveling at a speed of 724 km per hour at a bearing of N30°E. If the wind velocity is 32 km per hour from the west, find the resultant speed and direction of the plane.
Monday, February 23, 2015 at 8:20pm
I worked this problem out but I do not fully understand what I am doing. Fire tower A is 30 kilometers due west of fire tower B.. A fire is spotted from the towers, and the bearings from A and B are N 76 degrees E and N 56 degrees W, respectively. Find the distance d of the ...
Saturday, February 21, 2015 at 6:48pm
I am having trouble with this question. A privately owned yacht leaves a dock in Myrtke Beach, South Carolina, and heads toward Freeport in the Bahamas at a bearing of S 1.4 degrees E. The yacht averages a speed of 20 knots over the 428-nautical- mile trip. A. How long will it...
Saturday, February 21, 2015 at 6:18pm
I have been working on this problem but I am not sure I am doing it right. During takeoff an airplane's angle of ascent is 18 degrees and its speed is 275 feet per second. A. Find the plane's altitude after 1 minute. B. How long will it take for the plane to climb to ...
Saturday, February 21, 2015 at 12:13am
Quadratic equations Trig
I am having a hard time figuring this out. I know I need to find the vertex from the vertex form equation but I am having a hard time figuring out the equation. A caterer will charge a certain club $20 per member to cater a dinner if 150 members attend. However, the cost per ...
Wednesday, February 18, 2015 at 5:42pm
You need a 100 pounds of two types of candy that cost 50 cents per pound and 75 cents per pound. A.) Verify that your total cost is c(x)=0.50x + 0.75(100-x) thx a ton:)
Tuesday, February 17, 2015 at 11:52am
The system of equations: |z-2-2i|=sqrt(23), |z-8-5i|=sqrt(38) has two solutions z_1 and z_2 in complex numbers. Find (z_1+z_2)/2. My first instinct on this problem was to square each equation given that the square of the magnitude of a complex number is much easier to deal ...
Monday, February 16, 2015 at 3:58pm
From an observation tower that overlooks a runway, the angles of depression of point A, on one side of the runway, and point B, on the opposite side of the runway are 6 degrees and 13 degrees respectively. The points and the tower are in the same vertical plane and the ...
Thursday, February 12, 2015 at 9:24pm
What would an example of a logarithmic function that contains two trig functions within it where you would need to use chain rule and product rule to take derivative look like? How would taking the derivative of the function in its original form look different when using log ...
Thursday, February 12, 2015 at 12:13am
I am currently taking a trig class. I need help understanding how to solve for sin,cos, and tan in problems which give an angle and a side length or the hypotenus. Any help would be muchly appreciated
Wednesday, February 11, 2015 at 6:45pm
Find cotangent theta given that cosecant theta equals -3.5891420 and theta is in the third quadrant. I was using the trig identity 1+cot^2theta=csc^2theta I wanted to isolate cotangent so I plugged in 1/sin (-3.5891420) and then squared my answer. I then subtracted one from ...
Monday, February 9, 2015 at 6:18pm
A man is between two tall buildings 8m away from the taller building. If the angle of the top of the building from where he stans bears N 8degrees W for the taller one and N 12degrees E for other. How far is he from the other building if the taller building is 6/5 as to the other
Monday, February 9, 2015 at 5:45am
From post C, An airplane and a helicopter travel to different islands.The plane travels.415 km N 60degrees45minutes E to island A. and the helicopter travels to island B at S 19degrees5minutes E for 120 km. what is the distance between tthe two island
Monday, February 9, 2015 at 5:40am
Bob the ranger is atop a fire tower that i son the side of a mountain.The fire tower is 10 meters high and the angle of depression from the top of the tower to the base of the mountain is 48 degrees. The tower creates a 115 degree angle with the mountain. How far up he ...
Thursday, February 5, 2015 at 11:08pm
two ships p and q left a port at the same time. q sailed on a bearing of 150 while p sailed on the north side of q. after a distance of 8km and 10km by pand q respectively, their distance apart was 12km. find the bearing of p and r
Wednesday, February 4, 2015 at 1:05pm
I am having trouble with this question. I do not know where to begin. I am in Trig now and we are doing review but I forgot everything that I learned in Geometry. I want to understand how to do this problem. "a picture measures 20 cm by 25 cm. the width of the matting and...
Tuesday, January 27, 2015 at 9:53pm
I don't understand how to do these problems: Find two pairs of polar coordinates for each point with the given rectangular coordinates if 0 ≤ θ ≤ 2π. Round to the nearest hundredth, if necessary. 17. (2, -3) Answers: (3.61, 5.30) and (-3.61, 2.16) 19...
Wednesday, January 21, 2015 at 5:59pm
Two questions that I would really appreciate some hints on: 1) Circles with centers (2,1) and (8,9) have radii 1 and 9, respectively. The equation for a common external tangent can be written in the form y=mx+b with 0<m. What is b? 2) In triangle ABC, AB=BC, and BD is an ...
Tuesday, January 20, 2015 at 9:32pm
an observer at A looks due north and sees a meteor with an angle of elevation of 70 degrees. At the same instant, another observer 30 miles east of A seed the same meteor and approximates its position as N 50 degrees W but fails to note its angle of elevation. Find the height ...
Sunday, January 11, 2015 at 5:40am
a guy wire reaches from the top of a 125 meter television transmitter tower to the ground.The wire makes a 63' angle with the ground.Find the length of the guy wire.
Monday, January 5, 2015 at 8:09am
So I have two questions that have been puzzling me for quite some time and would really appreciate any help with either of them! (a) There are four positive intergers a, b, c, and d such that 4cos(x)cos(2x)cos(4x)=cos(ax)+cos(bx)+cos(cx)+cos(dx) for all values of x. ...
Sunday, January 4, 2015 at 1:46pm
A potato is put into an oven that has been heated to 350F. Its temperature as a function of time is given by T(t) = a(1 - e-kt) + b. The potato was 50F when it was first put into the oven. if the potato is 60F after 2 minutes, what is the value of k? ...
Tuesday, December 30, 2014 at 9:44pm
A body was found at 6 a.m. outdoors on a day when the temperature was 50oF. The medical examiner found the temperature of the body to be 66oF. What was the approximate time of death? Use Newton's law of cooling, with k = 0.1947. A. Midnight (12 a.m.) B. 5 a.m. C. 2 a.m. D...
Tuesday, December 30, 2014 at 9:30pm
Please help :) A potato is put into an oven that has been heated to 350F. Its temperature as a function of time is given by T(t) = a(1 - e-kt) + b. The potato was 50F when it was first put into the oven. What is the value of b in this context? Explain. What is ...
Monday, December 29, 2014 at 9:40pm
Find the greatest possible value of 5cos(x)+6sin(x). I know that it would be a good idea to look for identities that are in the form of acos(x)+bsin(x), but I can't seem to find any. Other than that I don't really know where to go with this problem. Any help would be ...
Tuesday, December 16, 2014 at 7:40pm
1. The sides of a triangle, in centimetres, are given by 3n-4, 3n+9, 4n+5. Draw a diagram to show the information. If the perimeter of the triangle is 114 cm, find the length of each side.
Thursday, December 11, 2014 at 10:27pm
Which of the following could be an example of a function with a domain (-oo,oo) and a range (-oo,2)? Check all that apply. A. y= -(3)^x+2 B. y= -(3)^x-2 C. y= -(0.25)^x+2 D/ y= -(0.25)^x-2
Tuesday, December 9, 2014 at 11:14am
Verify each trigonimetric equation by substituting identities to match right hand side of the equation to the hand side of the equation. Please help. -tan^2x+sec^2x=1
Monday, December 8, 2014 at 2:25pm
Please help me set up these problems. 1.) Find an equivalent equation in rectangular coordinates. r(1 - 2 cos θ) = 1 2.) Find a rectangular equation for the plane curve defined by the parametric equations. x = sec t, y = tan 3.) A projectile is fired with an initial ...
Monday, December 8, 2014 at 1:01am
1.) Find all solutions of the equation. Leave answers in trigonometric form. x^2 + 1 - sqrt3i = 0 2.) Give the rectangular coordinates for the point. (9, 2pi/3) 3.) The rectangular coordinates of a point are given. Express the point in polar coordinates with r L 0 and 0° K...
Monday, December 8, 2014 at 12:21am
1.) Write the complex number in trigonometric form r(cos theta + i sin theta) with theta in the interval [0°, 360°). 9 sqrt 3 + 9i 2.) Find the product. Write the product in rectangular form, using exact values. [4 cis 30°] [5 cis 120°] 3.) [4(cos 135° + i ...
Sunday, December 7, 2014 at 11:23pm
Question #1 Suppose that θ is an angle in standard position whose terminal side intersects the unit circle at −−2029,2129 Find the exact values of cscθ cotθ sinθ .
Saturday, December 6, 2014 at 2:49pm
2 roads intersect at an angle of 60 degrees. A friend's mail box is 434 feet from that intersection and your mailbox is on the other road and is 525 feet from the intersection. How far is it from your mailbox to your friend's mailbox? I got 1016.66 feet, but that is ...
Thursday, December 4, 2014 at 11:18pm