The Total solution for NCERT class 6-12
Let f(x) = x2 + x + 1 and g(x) =sin x. Show that fog ≠ gof.
Given f(x) = x2 + x +1 and g(x) = sin x
Now we have to provefog ≠ gof
(fog) (x) = f (g (x))
= f(sin x)
= sin2 x + sin x + 1
And (gof) (x) = g (f (x))
= g (x2+ x + 1)
= sin (x2+ x + 1)
So, fog ≠ gof.