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JEE MainMathematicsEasyFunctions

Let f:R→Rf:R \rightarrow R defined by
f(x)=x3+x2+100x+5sinxf(x) = x^{3} + x^{2} + 100x + 5sinx then function f(x) is

Show answer and solution
f′(x)=3x2+2x+100+5cosxf^{'}(x) = 3x^{2} + 2x + 100 + 5cosx
=3x2+2x+94+(6+5cosx)>0= 3x^{2} + 2x + 94 + (6 + 5cosx) > 0
∴\therefore f is strictly increasing hence one one also

Source: Grass-G / M-17 Mathematics Paper 26 Nov Second.docx

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