Given fx x2 2x 3 gx x 1 find fgx find fgxSolutionGiven t
Given f(x) = x^2 - 2x - 3: g(x) x + 1 find (fg)(x) find (f/g)(x)
Solution
Given that
f(x) = x2 - 2x - 3 , g(x) = x + 1
9 ) (fg)(x) = f(x).g(x)
= (x2 - 2x - 3)(x + 1)
= x3 + x2 -2x2 - 2x - 3x - 3
(fg)(x) = x3 - x2 - 5x - 3
10 ) Given that
(f/g)(x) = f(x)/g(x)
= (x2 - 2x - 3)/(x + 1)
= [ (x - 3)(x + 1) ] /(x + 1) [ since , x2 - 2x - 3 = x2 - 3x + x - 3 = x(x - 3) + 1(x-3) = (x-3)(x+1) ]
(f/g)(x) = x - 3
