Trigonometry-this section is not liked by almost all children. A huge number of trigonometric formulas that are not remembered in any way, and even tables of values of sin, cos, tg and ctg. And in General, I would like to note that most modern children are very lazy and they do not want to strain their brain convolutions. Yes, Yes, I mean you, dear students. I want to open one big secret, in mathematics, not everything is as scary as it seems. The first and one of the main things that you need to understand-the basics of trigonometry should be known to any person, since it is often encountered in everyday life. We meet with trigonometry in navigation and even in medicine and biology. Therefore, everyone should know at least the most basic of this course.
A table of values of sine, cosine, tangent and cotangent all teachers of mathematics zastavlyaut to teach. Especially since the OGE and the unified state exam in mathematics include tasks that test students ‘ knowledge in the field of trigonometry. Of course, this table can just sit and cram every day, as a result of which for a week, or maybe two, it will remain in your head. Then it still needs to be repeated periodically, so that for the exam, it does not fly out of your head.
There is another way to remember it. First, if you look closely at the table, you will notice that the value of the sine and cosine of the angle of 45 ° is the same. In the second place, the value of the sine of the angle 0 equal to the value of the cosine of the angle is 90º and the cosine of the angle 0 ° is equal to the value of the sine of the angle 0º. Now let’s talk about angles in 30º, 45º, 60º. In the values of the sine and cosine of these angles, there is always a fraction whose denominator is 2. And the numerator contains numbers from 1 to 3, with 2 and 3 standing under the root sign. The only difference is that in the values of the sine, the numbers in the numerator are arranged in the order of ingrowth, and in the values of the cosine – in descending order. As a result, in the exam, you can always draw a table of values of sine and cosine angles.
If you look at the values of tangent and cotangent, everything is also simple. The tangent and cotangent values for an angle of 45 ° are the same and equal to 1. And then diagonally:diagonally from right to left, the value is the root of 3, and from left to right of a fraction in which the numerator is the root of 3 and the denominator is 3. The tangent and cotangent values for 0º and 90º angles are stored in the same way as the sine and cosine values for these angles.
For angles of 180º, 270º and 360º the values are arranged in a staggered manner. That’s how easy and simple it is to remember a bird.