Sine and Cosine

Sine, Cosine and Tangent are all based on a Right-Angled Triangle.

Before getting stuck into the functions, it helps to give a name to each side of a right triangle: triangle showing Opposite, Adjacent and Hypotenuse

"Opposite" is opposite to the angle θ"

Adjacent" is adjacent (next to) to the angle θ

"Hypotenuse" is the long one.

For a triangle with an angle θ, they are calculated this way:

Sine Function:sin(θ) = Opposite / Hypotenuse

Cosine Function:cos(θ) = Adjacent / Hypotenuse

It is important to memorize 45, 45, 90 triangles and their corresponding sides and well as the sides of 30, 60, 90 triangles.

Math Joke of the week 

Applying For A Job 

There are three people applying for the same job. One is a mathematician, one a statistician, and one an accountant. The interviewing committee first calls in the mathematician. They say "we have only one question. What is 500 plus 500?" The mathematician, without hesitation, says "1000." The committee sends him out and calls in the statistician. When the statistician comes in, they ask the same question. The statistician ponders the question for a moment, and then answers "1000... I'm 95% confident." He is then also thanked for his time and sent on his way. When the accountant enters the room, he is asked the same question: "what is 500 plus 500?" The accountant replies, "what would you like it to be?" They hire the accountant.