Trigonometry mainly provides six functions for sine (sin), cosine (cos), and tangent (tan), also its reciprocal functions cosecant (csc), secant (sec), and cotangent (cot). These processes help in solving angle and distance related problems in both 2D and 3D surroundings.

To solve a trigonometric simplify the equation using trigonometric identities. Then, write the equation in a standard form, and isolate the variable using algebraic manipulation to solve for …

Free math problem solver answers your trigonometry homework questions with step-by-step explanations.

Compute answers using Wolfram's breakthrough technology & knowledgebase, relied on by millions of students & professionals. For math, science, nutrition, history, geography, engineering, mathematics, linguistics, sports, finance, music…

Sep 27, 2021 · If $\theta = -\pi$, the point would still have coordinates $(-1, 0)$ i.e. cos $(-\pi) = -1$. This is because rotating something $\pi$ counterclockwise is equivalent to rotating something $\pi$ clockwise, as mentioned by Cameron Williams in the comments.

Yes, indeed: \cos(-2\pi) = \cos(2\pi) = 1. Formally, this is because \cos \theta is an even function, meaning \cos\theta = \cos(−\theta) for all \theta. This can be seen in a number of ways. ...

Why are cos (π) and cos (-π) both equal to -1? Solution: In trigonometry, cosine is an angle complementary to a sine angle. It is defined as a ratio of adjacent (base) sides to the hypotenuse. As we know that, cos(π) = cos 180º. cos 180º lies in the second quadrant where cos has a negative value. Therefore, cos (π) or cos 180º = -1

If $\pi/2 < \theta < 3\pi/2$ $\cos \theta$ is negative, because its length is in fact negative as the line representing $\cos$ is left of the y axis. If you are familiar with radians, $\pi$ is $180$ degrees.

The "opposite" side, $S_2$ has length $0$, the "adjacent" side, $S_1$ has length $1$, and the "hypotenuse," $S_3$ length $-1$, and thus $\cos(-\pi) = \frac{1}{-1} = -1$. Alternative definitions of $\cos$ can give us different ways of thinking about it.

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant. Make the expression negative because cosine is negative in the second quadrant. The exact value of cos(0) cos (0) is 1 1. Multiply −1 - 1 by 1 1.