Trigonometry mainly but also geometry, algebra.
It helps, in this type of problem, to convert all trigonometric functions to sines and cosines. As a reminder, tan(x) = sin(x) / cos(x).
For a start, try converting everything to sines and cosines.
Law of sines or cosines SinA/a=SinB/b=SinC/c
Having sufficient angles or sides one can use either, The Law of Sines, or, The Law of Cosines. Google them.
In trigonometry sines and cosines are used to solve a mathematical problem. And sines and cosines are also used in meteorology in estimating the height of the clouds.
Trigonometry mainly but also geometry, algebra.
It helps, in this type of problem, to convert all trigonometric functions to sines and cosines. As a reminder, tan(x) = sin(x) / cos(x).
For a start, try converting everything to sines and cosines.
The ACT asks questions about basic sines, cosines, and tangents. These questions can be answered without a calculator.
Law of sines or cosines SinA/a=SinB/b=SinC/c
Use Law of Sines if you know:Two angle measures and any side length orTwo side lengths and a non-included angle measure.Use Law of Cosines if you know:Two side lengths and the included angle measure orThree side lengths.
It's an infinite sum of sines and cosines that can be used to represent any analytic (well-behaved, like without kinks in it) function.
Every periodic signal can be decomposed to a sum (finite or infinite) of sines and cosines according to fourier analysis.
When none of the angles are known, and using Pythagoras, the triangle is known not to be right angled.
I suggest you convert everything to sines and cosines, and then try to simplify. For example, sec x = 1 / cos x, tan x = sin x / cos x, etc. Then - depending on the problem requirements - you either verify whether they are always equal or not, or determine for what values of x they are equal.
Having sufficient angles or sides one can use either, The Law of Sines, or, The Law of Cosines. Google them.