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High School Archive

Browse High School Trigonometry
Stars indicate particularly interesting answers or good places to begin browsing.

Selected answers to common questions:
    DeMoivre's theorem.
    Volume of a tank.

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Trigonemetric Identities [02/11/2003]

I'm struggling with the concepts of compound angle formulas, products of sums or differences, and multiple and half angles. Is there a connection between these and all the trig identities?

Trigonometric Equation [8/11/1995]

Solve {x : 2sin(3x-1)+7 = 6.25, -Pi<x<Pi}.

Trigonometric Equation for a Sequence [04/03/2001]

I need an equation for the sequence 0, 0, 1, 0, 0, 1, 0, 0, 1, ... using the sine or cosine function.

Trigonometric Formulas [2/1/1996]

My question concerns trigonometric formulas. How do I show how the double angle formulas are derived from the compound angle formulas?

Trigonometric Functions and Complex Numbers [6/27/1995]

Is there a solution to the following equation? Sin(a) = 5, where a = x + iy (complex value)

Trigonometric Functions and Euler's Identity [04/10/1998]

We need to prove three trigonometric functions in various ways.

Trigonometric Identiity [07/29/1999]

Prove arcsin(-x)= -arcsin(x).

Trigonometric Identities [11/12/1997]

What is the best way to solve verification problems?

Trigonometric Identities [12/10/1997]

How do you prove sin(t+s)sin(t-s) = sin^2t-sin^2s ?

Trigonometric Identities [05/24/1999]

How can I simplify trigonometric identity problems such as sin^ 2(theta) - 1?

Trigonometric Identity [02/12/1998]

Prove that sin 7x = 7(sin x) - 56(sin x)^3 + 112(sin x)^5 - (sin x)^7.

Trigonometric Proofs [09/13/2004]

How do I prove that (sinA - sinB)/(cos A + cosB) = tan(A/2 - B/2)?

Trigonometry -- Airport Word Problems [6/6/1996]

A plane is 120 miles north and 85 miles east of an airport.... When an airplane leaves the runway, its angle of climb is 18 degrees and its speed is 275 feet per second...

Trigonometry and Complex Numbers [08/05/1998]

Simplify (sqrt 3 - i)^7 into the form a + bi using DeMoivre's Theorem.

Trigonometry and Music [12/21/1998]

How is trigonometry used in music?

Trigonometry and Navigation [3/29/1995]

I have a research project to write about the uses of trigonometry in the field of navigation.

Trigonometry and Space Exploration [05/29/2002]

How does Trigonometry relate to space exploration?

Trigonometry and Telescopes [12/15/2001]

How is trigonometry related to how reflector and refractor telescopes work?

Trigonometry and the Chain Rule [12/01/1998]

I need help differentiating expressions such as: y = 2 csc^3(sqrt(x)) and y = x/2 - (sin (2x))/4. Where does the chain rule fit in?

Trigonometry and the Earth [07/13/1999]

A woman 6 ft. tall stands at the edge of the ocean. The radius of the earth is 3960 miles. How far out can she see?

Trigonometry by Hand [05/24/2002]

What formulas can I use to compute sines, cosines, tangents, arcsines, arccosines, and arctangents without using tables or a calculator?

Trigonometry Equations [04/23/2003]

Solve, for 0 <= theta < 360, 3cos^2(theta) - 2sin(theta) = 2, giving solutions to 1 decimal place where appropriate.

Trigonometry + Geometry [5/5/1996]

A right angle triangle is blocking a circle and is being blocked by another circle...

Trigonometry Identities [01/07/1997]

Verify the identity sin(x+y+z) = sinx cosy coxz + cosx siny cosz + cosx cosy sinz - sinx siny sinz.

Trigonometry Identities [07/30/1997]

I have a problem with these identities...

Trigonometry Identity [02/20/1998]

Prove a*cos(A) + b*cos(B) + c*cos(C) = 4R*sin(A)*sin(B)*sin(C).

Trigonometry, Logs and Map Projections [10/01/1997]

I am trying to figure out the inverse function used by the Mercator map projection.

Trigonometry Mnemonic [04/12/1997]

How do you spell the trigonometry word that is something like SOCHOATOA? It means side over hypotenuse, etc.

Trigonometry Problem [8/11/1995]

A 12 metre ladder is inclined to the vertical at 48 degrees. How far is it from the base?

Trigonometry Proof [6/20/1996]

Prove that if a,b,y > 0 and a+b+y = pi, then sin(2a)+sin(2b)+sin(2y) = 4(sin a)(sin b)(sin y)

Trigonometry Proof [7/18/1996]

How do I prove that (cotX)(cosX)/(cotX + cosX) = (cosX)/(1 + sinX)?

Trigonometry Proof [04/21/1997]

Prove that (sin 50 x cos 50)/tan 50 = sin^2 40.

Trigonometry Story Problem [06/04/2002]

What angle will a shortcut make with the roads nearest it?

Trigonometry Substitutions [09/30/1997]

I am having problems doing trig substitutions. Can you suggest any methods?

Trigonometry Terminology [10/24/2001]

Why is the term 'arc' used for the inverse of sine, cosine, and tangent, instead of just saying the function to the -1 power?

Trigonometry Tricks [11/14/2002]

To find how (1/4)cos^4x-(1/6)cos^6x = -(1/4)sin^4x+(1/6)sin^6x, I've tried to change all the cos to sin by using sin^2x+cos^2x = 1 and then using double angle formulas. I am trying to prove that they are equal to each other.

Trigonometry Without Calculators [01/06/1997]

How do you find Cos[40] without a calculator?

Trigonometry Word Problem [06/05/2002]

How far did the hot-air balloon rise between observations?

Trig Problems [05/07/1999]

What are the steps to follow in order to answer these questions? 1) cos2x = sinx; 2) cos2x = cosx...

Trig Problem: Sec A = -2 ... [10/20/1997]

How can I find all the angles in the range between 0 and 2*pi radians that have a secant equal to -2?

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