Table of Contents
How do you know whether to use Sin Cos or tan?
Just remember soh, cah, toa: If you have the hypotenuse and the opposite side, then use sine. If you have the hypotenuse and the adjacent side, then use cosine. If you have the adjacent and the opposite sides, then use tangent.
Can sin cos and tan be used for non right triangles?
However, these methods do not work for non-right angled triangles. For non-right angled triangles, we have the cosine rule, the sine rule and a new expression for finding area. In order to use these rules, we require a technique for labelling the sides and angles of the non-right angled triangle.
Does trigonometry only work with right angles?
Q: Is sohcahtoa only for right triangles? A: Yes, it only applies to right triangles. If we have an oblique triangle, then we can’t assume these trig ratios will work. We have other methods we’ll learn about in Math Analysis and Trigonometry such as the laws of sines and cosines to handle those cases.
How do you know when to use inverse trig functions?
The inverse trigonometric functions sin−1(x) , cos−1(x) , and tan−1(x) , are used to find the unknown measure of an angle of a right triangle when two side lengths are known.
What angle has tan?
Commonly used angles
| Angle in degrees | Tangent value |
|---|---|
| 45° | 1 |
| 60° | |
| 75° | |
| 90° | Undefined |
What is the difference between Cos and sin and Tan?
Cos= adjacent / hypotenuse. Sin= opposite / hypotenuse. Tan= opposite / adjacent. In order to find out which sides you have lengths for already, you need to look at where you angle degree is placed.
How do you know when to use cosine and tangent?
If you have the hypotenuse and the adjacent side, then use cosine. If you have the adjacent and the opposite sides, then use tangent. Or, if you have any two numbers from the first group, (let’s say you have an angle and the hypotenuse and you need to find the length of the opposite side), then use that group.
Is sine a trigonometric function?
The sine function is a trigonometric function. The sine of a given angle in a right triangle is the ratio of the length of the opposite side to the length of the hypotenuse. The sine function is defined by the formula: Here, the S stands for S in θ, the O for O pposite and the H for H ypotenuse (from the SOH in SOH CAH TOA).
How do you find the adjacent and opposite sides of sin 30?
A quick check when calculating the adjacent and opposite sides is to make sure that your answer is less than the length of the hypotenuse. Find the length of the side BC. Side BC is opposite the 30° angle. We also know the hypotenuse is 7 cm in length. We must use the equation for sin: