Mark the correct alternative in the following:

The function f(x) = x^{9} + 3x^{7} + 64 is increasing on

Formula:- (i) The necessary and sufficient condition for differentiable function defined on (a,b) to be strictly increasing on (a, b) is that f’(x)>0 for all x(a,b)

Given:-

f(x) = x^{9} + 3x^{7} + 64

For increasing f’(x)>o

9x^{8}+21x^{6}>0

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