A boring broadcast on quiet times is often part of this formula (8)
I believe the answer is:
equation
'times is often part of this formula' is the definition.
'equation' can be an answer for 'formula' (I've seen this before). I'm not certain of the rest of the definition.
'a boring broadcast on quiet' is the wordplay.
'boring' means one lot of letters goes inside another (some letters must 'bore' a hole into other letters).
'broadcast' indicates anagramming the letters (letters scattered or cast around).
'on'+'quiet'='onquiet'
'onquiet' is an anagram of 'eqution'.
'a' going within 'eqution' is 'EQUATION'.
Can you help me to learn more?
(Other definitions for equation that I've seen before include "Mathematical statement that two expressions are equal" , "E.g. 2 + 2 = 4" , "Mathematical statment that two are equal" , "Mathematical relationship" , "V=IR, say" .)