Find inverse of f(x)=6x^2+4 over the domain (-infinity,0)

Inverse for x is negative
well, since x is squared, it doesn't matter snce (-)^2=(+)

inverse
replace f(x) with y
solve for x
replace x with f invers aka f⁻¹(x) and y with x

y=6x^2+4
minus 4
y-4=6x^2
divide 6
(y-4)/6=x^2
squaer root both sides
=x
replace x with f⁻¹(x) and replace y with x
f⁻¹(x)=

Where’s the table? be more specific so we can you