Find the value(s) of x for which y =  is an increasing function. - Zigya
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Find the value(s) of x for which y = open square brackets straight x left parenthesis straight x minus 2 right parenthesis close square brackets squared is an increasing function.


Given function is
straight f left parenthesis straight x right parenthesis space equals space open square brackets straight x left parenthesis straight x minus 2 right parenthesis close square brackets squared
rightwards double arrow space straight f apostrophe left parenthesis straight x right parenthesis space equals space straight x squared cross times space 2 left parenthesis straight x minus 2 right parenthesis plus left parenthesis straight x minus 2 right parenthesis squared cross times space 2 straight x
rightwards double arrow straight f apostrophe left parenthesis straight x right parenthesis space equals space 2 straight x left parenthesis straight x minus 2 right parenthesis space open square brackets straight x plus left parenthesis straight x minus 2 right parenthesis close square brackets
rightwards double arrow straight f apostrophe left parenthesis straight x right parenthesis space equals space 2 straight x left parenthesis straight x minus 2 right parenthesis left square bracket 2 straight x minus 2 right square bracket
rightwards double arrow straight f apostrophe left parenthesis straight x right parenthesis space equals space 2 straight x left parenthesis straight x minus 2 right parenthesis thin space open square brackets 2 left parenthesis straight x minus 1 right parenthesis close square brackets
rightwards double arrow straight f apostrophe left parenthesis straight x right parenthesis space equals 4 straight x left parenthesis straight x minus 1 right parenthesis left parenthesis straight x minus 2 right parenthesis

Since space straight f apostrophe left parenthesis straight x right parenthesis space is space an space increasing space function comma space straight f apostrophe left parenthesis straight x right parenthesis greater than 0
rightwards double arrow space space straight f apostrophe left parenthesis straight x right parenthesis space equals space 4 straight x left parenthesis straight x minus 1 right parenthesis thin space left parenthesis straight x minus 2 right parenthesis greater than 0
rightwards double arrow straight x left parenthesis straight x minus 1 right parenthesis space left parenthesis straight x minus 2 right parenthesis thin space greater than 0
rightwards double arrow 0 less than straight x less than 1 space or space straight x greater than 2
rightwards double arrow straight x space element of space left parenthesis 0 comma space 1 right parenthesis space union space left parenthesis 2 comma space infinity right parenthesis

 
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