Question

Question on presentation. Thanks :D

Answer 1

For partial fractions, I understand that there are some points where you are supposed to use a 3 line equal sign instead of the regular equal sign. When do you use the 3 line one?

Answer 2

@phi

Answer 3

do you mean \( \equiv \) versus = ?

Answer 4

yup. couldn't find the sign

Answer 5

I think the \( \equiv\) means "identically equal" , and I think of it as meaning "defined as"
I'm not sure it really matters

btw, in latex the symbol is \equiv

Answer 6

but it does matter to my teachers apparently? But it wouldn't be wrong to say \[\frac{ 3x+1 }{ 2 }\equiv \frac{ 2x }{ 5x }\] assuming the two are equal. (it's a rubbish equation i know but let's ignore that)

Answer 7

I would only use the identically equal sign if the expression is true for *all x* , not just one specific value.

for example, this would be a valid use
\[ \sin^2 x + \cos^2 x \equiv 1 \]

Answer 8

ah I see. Ok thank you :D

Answer 9

or if you wanted to claim two functions are identical
\[ f(x) \equiv g(x) \]
which means that f(x) and g(x) are identical. this is different from writing
\[ f(x)= g(x) \]
which is (1) true (for some value(s) of x) or (2) not true (no value of x makes the statement true)

Answer 10

THANK YOU :D