- Home
- Standard 12
- Mathematics
Consider a function $f:\left[ { - 1,1} \right] \to R$ where $f(x) = {\alpha _1}{\sin ^{ - 1}}x + {\alpha _3}\left( {{{\sin }^{ - 1}}{x^3}} \right) + ..... + {\alpha _{(2n + 1)}}{({\sin ^{ - 1}}x)^{(2n + 1)}} - {\cot ^{ - 1}}x$ Where $\alpha _i\ 's$ are positive constants and $n \in N < 100$ , then $f(x)$ is
one-one and onto
one-one and into
many one and onto
many one and into
Solution
$ \frac{\mathrm{dy}}{\mathrm{dx}}=\frac{\alpha_{1}}{\sqrt{1-\mathrm{x}^{2}}}+ \frac{\alpha_{3}\left(3 \sin ^{-1} \mathrm{x}\right)^{2}}{\sqrt{1-\mathrm{x}^{2}}}+\ldots \ldots $
$+\frac{(2 \mathrm{x}+1)\left(\sin ^{-1} \mathrm{x}\right)^{2 n}}{\sqrt{1-\mathrm{x}^{2}}}+\frac{1}{\left(1+\mathrm{x}^{2}\right)} $
$\frac{\mathrm{d} y}{\mathrm{dx}}>0$ and function is one one
but range $\neq$ codomain
$\Rightarrow$ into fumction
