Question

Question #4c80c

Answer 1

False.

Explanation:

An identity has to be true for all values of the variable for which it is an identity.

`cos(x)=sqrt(3)/2`

is just an equation, and is only true for certain value of `x`. In this case values could be `pi/6, (11pi)/6.`

This is an identity:

`color(red)(tan(x)=sin(x)/cos(x))`

This is true for all `x`.

Sometimes identities are written using `-=` instead of `=`, so they can be easily identified.

Identities are often just a different way of expressing the same thing.

Example:

`x^2+5x+6`

If we factor this:

`(x+3)(x+2)`

We can then write:

`x^2+5x+6-=(x+3)(x+2)`

We know this will be true for all `x`, since it is just the same expression in different forms.