Can someone explain sin and cos functions to me?

Question

also explain this graph http://www.biologydaily.com/biology/upload/1/13/Sine_Cosine_Graph.png

Answer 1

Don't be afraid, it's quite simple. We assume that we draw on paper a circle with a radius = 1. We choose one point on that circle. If we draw a straight line from the center of a circle to that point, and another one from that point rectangular to the radius, we obtain a triangle. If the point is A, the center is O and other point of the circle we named B, the sin function value is equal to the segment AB of the triangle, and the cos value is equal to the section OB of the triangle. The angle that is formed between the OB and OA segments is called the function argument. So, if that angle is 45 degrees, or, in math terms, pi / 4 = 180 degrees divided by 4 = 45 degrees, we say that sin(pi/4) = sqrt(2)/2. The prove is easy if you are familiar with Pythagoras's theorem, that states that OA^2=OB^2 + AB^2, in our case. Now, [sqrt(2)/2]^2 + [sqrt(2)/2]^2 = 2/4 + 2/4 = 1, the EXACT size of OA = the radius we choose. I hope i wasn't too hard to understand..but we can talk more about it if u like, i'm a math teacher.

Answer 2

You use these when you are working with right triangles. Sin equals the opposite side of the triangle divided by the hypotenuse. The Cos function is similar. It equlas the adjacent side of the triangle divided by the hypotenuse. If you are given both sides, you can plug them in to find the angle. If the angle is given along with one side, you can substitue in and find the other side. I'm sorry but I couldn;t see the graph. I hope this helps you!

Answer 3

Sine and cosine are the trigonometric functions.Checkout the link for more information.About the graph it just explains Sine and cosine functions.Sine waveform starts from 0 and completes a cycle in 2(pi) 0r 360.But the cosine wave leads Sine wave by 90 thats why it starts in -90.If sine waveform starts by 90 then cosine will start by 0.All household electrical signals that is the output of your house electrical outlet is a sine waveform.

Answer 4

Easy way to understand Sine and Cosine functions:

Draw a CIrcle with radius r.

The distance from the center of the circle to any point on the circle can be represented as an ordered pair (r *cosine of an angle theta, r* sine of an angle theta) where the ordered pair is the coordinates of the selected point on the circle

Answer 5

Sine and cosine are ratios derived from a right triangle. Sine is defined as the ratio of the length of the side opposite the angle to the length of the hypotenuse, cosine is the ratio of the side adjacent to the angle to the length of the hypotenuse.

Answer 6

well sin is equal to opposite divided by hypotenuse and cos is equal to adjacent divided by hypotenuse.......jus plug the values for these into ur calculator whenevr u solving a math problem.........NB. the adjacent is usually the adjoining angle to the angle in question and the hypotenuse is the longest side of a triangle.....hope this helps....chao

Answer 7

Is that Trigonometry? I remember bits of that. Tommy on a ship of his caught a herring. That means that Tan is opposite over adjacent, Sin is opposite over hypotenuse and Cos is adjacent over hypotenuse.

Answer 8

it is part of Trigonometry. Tan is opposite over adjacent, Sin is opposite over hypotenuse and Cos is adjacent over hypotenuse.

i remember it by soh toa cah

hope this helps

Answer 9

You've gotta memorize the sines and cosines of certain angles in radians. Once you know that, you simply solve the inside first, then the outside.

Answer 10

yes i could