find number that arent the domain if the function
f(y)=(2y-9)/(7y+6)

Question

find number that arent the domain if the function
f(y)=(2y-9)/(7y+6)

hartnn · Answer

the number for which the denominator of f(y) equals to 0 will NOT be in the domain.
so, can you solve, 7y+6= 0 ?

anonymous · Answer

6/7?

hartnn · Answer

almost!
 try once again ? hint : be careful with signs.

anonymous · Answer

oh ok its negative 6/7

hartnn · Answer

thats correct,
so x=-6/7 is the number not in the domain of f(y)
thats it!
any doubts ?

hartnn · Answer

** y= -6/7

anonymous · Answer

ok so just solve for the denominator to be undefined I got it

hartnn · Answer

good, well actually there are 2 things to consider in GENERAL,
1) denominator should NOT= 0
2) the quantity under the square root sign must be NON-NEGATIVE 
here there was no square root sign, so we just considered 1).

hartnn · Answer

and solve for denominator to be ZERO 
for which f(y) is undefined....