Sine sum identity: sin (x + y) = (sin x)(cos y) + (cos x)(sin y)
Sine difference identity: sin (x - y) = (sin x)(cos y) - (cos x)(sin y)
Cosine sum identity: cos (x + y) = (cos x)(cos y) - (sin x)(sin y)
Cosine difference identity: cos (x - y) = (cos x)(cos y) + (sin x)(sin y)
Tangent sum identity: tan (x + y) = [(tan x) + (tan y)]/[1 - (tan x)(tan y)]
Tangent difference identity: tan (x - y) = [(tan x) - (tan y)]/[1 + (tan x)(tan y)]
I find it convenient to express other trigonometric functions in terms of sine and cosine - that tends to simplify things. The secant function is even because it is the reciprocal of the cosine function, which is even. The tangent function is the sine divided by the cosine - an odd function divided by an even function. Therefore it is odd. The cosecant is the reciprocal of an odd function, so it is naturally also an odd function.
"COS" stands for "Cosine", which is one of the 6 trigonometric functions. Similarly, "SIN" stands for Sine, and TAN stands for Tangent.
A way to remember the definitions of the three most common trigonometry functions: sin, cos and tan. Used as a memory aid for the definitions of the three common trigonometry functions sine, cosine and tangent.
The tangent of an angle theta is defined as sine(theta) divided by cosine(theta). Since the sine and cosine are Y and X on the unit circle, then tangent(theta) is Y divided by X. The tangent of a function at a point is the line going through that point which has slope equal to the first deriviative of the function at that point.
Sine Cosine Tangent Cotangent Secant Cosecant
They are different trigonometric functions!
sine, cosine, tangent, cosecant, secant and cotangent.
Sine, Cosine, Tangent, Cotangent, secant and cosecant
The basic functions of trigonometry are: sine cosine tangent secant cosecant cotangent
Sine Cosine Tangent ArcSine ArcCosine ArcTangent
Tangent = sine/cosine provided that cosine is non-zero. When cosine is 0, then tangent is undefined.
You can use your trigonometric functions (sine, cosine, and tangent).
The basic circular functions are sine, cosine and tangent. Then there are their reciprocals and inverses.
sine, cosine, tangent, cosecant, secant and cotangent.
The trigonometric functions are sine, cosine and tangent along with their reciprocals and the inverses. Whether the angle is acute or obtuse (or reflex) makes no difference).
If you know the angle's sine, cosine, or tangent, enter it into the calculator and press <inverse> sine, cosine, or tangent. On MS Calc, in Scientific Mode, using Degrees, enter 0.5, then check Inv and the press sin. You should get 30 degrees. The other functions work similarly.
It isn't clear what you want to solve for. To solve trigonometric equations, it often helps to convert other angular functions (tangent, cotangent, secant, cosecant) into the equivalent of sines and cosines. However, the details of course depend on the specific case.