 # Question: How Do You Prove Pythagorean Identity?

## How do you prove an identity?

An “identity” is a tautology, an equation or statement that is always true, no matter what.

For instance, sin(x) = 1/csc(x) is an identity.

To “prove” an identity, you have to use logical steps to show that one side of the equation can be transformed into the other side of the equation..

## Why are Trig identities so hard?

In fact it’s rather basic mathematics. However if all you know is arithmetic and basic linear algebra then yes trigonometry seems more difficult. The reason is that unlike linear algebra (solving linear equations) trigonometry is non-linear which makes the identities between multiples of angles non-trivial.

## What are examples of identities?

Examples of identities include heterosexual, gay, lesbian, bisexual (people who are attracted to people of two genders), pansexual (a term referring to the potential for attractions or love toward people of all gender identities and sexes), asexual (people who either do not feel sexual attraction or do not feel desire …

## What does SOH CAH TOA mean?

Sine equals Opposite over Hypotenusewebsite feedback. SOHCAHTOA. A way of remembering how to compute the sine, cosine, and tangent of an angle. SOH stands for Sine equals Opposite over Hypotenuse. CAH stands for Cosine equals Adjacent over Hypotenuse.

## What are the 3 basic trigonometric functions?

The three main functions in trigonometry are Sine, Cosine and Tangent.

## What are the 3 Pythagorean identities?

Pythagorean identitiesBasic Concepts.Use sine ratio to calculate angles and sides (Sin = o h \frac{o}{h} h o​ )Use cosine ratio to calculate angles and sides (Cos = a h \frac{a}{h} h a​ )Factoring difference of squares: x 2 − y 2 x^2 – y^2 x2−y2.Unit circle.

## What does it mean to prove a trigonometric identity?

Proving a trigonometric identity refers to showing that the identity is always true, no matter what value of x x x or θ \theta θ is used. Because it has to hold true for all values of x x x, we cannot simply substitute in a few values of x x x to “show” that they are equal.

## What are the six basic trigonometric functions?

There are six main trigonometric functions:Sine (sin)Cosine (cos)Tangent (tan)Secant (sec)Cosecant (csc)Cotangent (cot)

## How do you do good trigonometric identities?

5 strategies you can use to solve TRIG IDENTITIESSee what you can FACTOR. Ernest Wolfe. … Multiply the denominator by a CONJUGATE. … Get a COMMON DENOMINATOR. … SPLIT UP A FRACTION into two separate fractions. … Rewrite everything in terms of SINE AND COSINE.

## What does sin 2x equal?

1. sin(2x)=2sin(x)cos(x).