$\begin{aligned}
& f(f(x))=\frac{2 f(x)}{\sqrt{1+9 f^2(x)}}=\frac{4 x}{\sqrt{1+9 x^2+9.2^2 x^2}} \
& f(f(f(x)))=\frac{2^3 x / \sqrt{1+9 x^2}}{\sqrt{1+9\left(1+2^2\right) \frac{2^2 x^2}{1+9 x^2}}}=\frac{2^3 x}{\sqrt{1+9 x^2\left(1+2^2+2^4\right)}}
\end{aligned}\thereforeByobservation\begin{aligned}
& \alpha=1+2^2+2^4+\ldots .+2^{18}=1\left(\frac{\left(2^2\right)^{10}-1}{2^2-1}\right)=\frac{2^{20}-1}{3} \
& 3 \alpha+1=2^{20} \rightarrow \sqrt{3 \alpha+1}=2^{10}=1024
\end{aligned}$
Consider the function f: mathbbR → mathbbR defined by f(x)= 2 x √1+9 x^2. If the composition of f, underbrace(f ° f ° f ° … ° f)_10 times (x)= 2^10 x…
JEE Main 2024 — Mathematics Algebra
Consider the function f:R→R defined by f(x)=1+9x22x. If the composition of f,10 times (f∘f∘f∘⋯∘f)(x)=1+9αx2210x, then the value of 3α+1 is equal to ______
Held on 4 Apr 2024 · Verified 6 Jul 2026.
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