Let fx 7x gx 2x1x3 Find g of f and its domainSolutionfx 7x
Let f(x)= 7/x , g(x) = (2x+1)/(x-3)
Find g of f and its domain.
Solution
f(x)= 7/x , g(x) = (2x+1)/(x-3)
(g o f)(x): Plug x = f(x) in g(x)
(g o f) (x) = (2*7/x +1)/ (7/x -3)
=(14 +x)/ (7 - 3x)
Domain : denominator should not be zero: so, 7- 3x =0
x = 7/3
So, domian = ( -inf, 7/3) U ( 7/3, inf)
