If f : R → R and g : R → R are two functions defined by f x = a x + b a ≠ 0 ∀ x…

If f:RR and g:RR are two functions defined by fx=ax+ba0xR and gx=cx3+dc0xR, then fog-1x=
  1. x-ad+bac12
  2. x+ad-bac13
  3. x-ad-bac13
  4. x+ad+bac13

Solution

Given, fx=ax+b and gx=cx3+d

fogx=fgx

fogx=agx+b

=acx3+d+b

Let, y=acx3+ad+b

x3=y-ad-bac

x=y-ad-bac13

Hence, fog-1x=x-ad-bac13

Asked in: AP EAMCET 2021 (20 Aug Shift 2)

Practice more Functions questions on Aicharya