# If $f(x)= x^3;$  $g(x)= 2x$ . Then evaluate gof(x)+ fog (x)  Option 1) $8x^{3}+x^{9}$ Option 2) $10x^{3}$ Option 3) $3x^{3}$ Option 4) $5x^{2}$

As we have learned

Properties of composite function -

The composition of function is not commutative.

- wherein

$f\! og \neq g\: o\! f$

fog(x)= f(2x)= $(2x)^3$

gof(x) = g$(x)^3$$(2x)^3$

$\Rightarrow fog (x) +gof (x) = 8x^3+ 2x^3= 10 x^3$

Option 1)

$8x^{3}+x^{9}$

Option 2)

$10x^{3}$

Option 3)

$3x^{3}$

Option 4)

$5x^{2}$

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