(A) Given that $f: R \rightarrow R$ is an injective function satisfying $f(x) f(y) = f(x+y)$ for all $x, y \in R$. This functional equation is satisfi

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(A) Given that $f: R \rightarrow R$ is an injective function satisfying $f(x) f(y) = f(x+y)$ for all $x, y \in R$. This functional equation is satisfied by the exponential function $f(x) = a^x$ for some $a > 0, a \neq 1$. Since $f(x), f(y), f(z)$ are in $G$.$P$.,we have $(f(y))^2 = f(x) \cdot f(z)$. Substituting $f(x) = a^x$,we get $(a^y)^2 = a^x \cdot a^z$. This simplifies to $a^{2y} = a^{x+z}$. Equating the exponents,we get $2y = x+z$. This condition implies that $x, y, z$ are in $A$.$P$.

Class 12 Mathematics Relation and Function Functional Equations

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Let $f: R \rightarrow R$ be such that $f$ is injective and $f(x) f(y) = f(x+y)$ for $\forall x, y \in R$. If $f(x), f(y), f(z)$ are in $G$.$P$.,then $x, y, z$ are in:

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$AP$ depending on the value of $x, y, z$
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$GP$ depending on the value of $x, y, z$

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$f: R \rightarrow R$ is a function such that $f(0)=1$ and for all $x, y \in R$,$f(xy+1)=f(x)f(y)-f(y)-x+2$. Then $\frac{df}{dx}$ at $x=e$ is:

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Let $f$ and $g$ be functions satisfying $f(x+y)=f(x)f(y)$,$f(1)=7$ and $g(x+y)=g(xy)$,$g(1)=1$ for all $x, y \in \mathbb{N}$. If $\sum_{x=1}^{n} \left(\frac{f(x)}{g(x)}\right) = 19607$,then $n$ is equal to:

DifficultJEE MAIN 2026

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If $f: R \rightarrow R$ is defined as $f(x+y)=f(x)+f(y)$,$\forall x, y \in R$ and $f(1)=5$,then find the value of $\sum_{r=1}^n f(r)$.

EasyAP EAMCET 2021

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Find $\sum_{t=1}^{39} f(t)$ if $f: R \rightarrow R$ is defined as $f(x+y)=f(x)+f(y)$ for all $x, y \in R$ and $f(1)=7$.

MediumAP EAMCET 2020

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Let $f$ be a polynomial function such that $\log_2(f(x)) = (\log_2 (2 + \frac{2}{3} + \frac{2}{9} + \dots \infty)) \cdot \log_3 (1 + \frac{f(x)}{f(1/x)}), x > 0$ and $f(6) = 37$. Then $\sum_{n=1}^{10} f(n)$ is equal to:

DifficultJEE MAIN 2026

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Let $f: R \rightarrow R$ be such that $f$ is injective and $f(x) f(y) = f(x+y)$ for $\forall x, y \in R$. If $f(x), f(y), f(z)$ are in $G$.$P$.,then $x, y, z$ are in:

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$f: R \rightarrow R$ is a function such that $f(0)=1$ and for all $x, y \in R$,$f(xy+1)=f(x)f(y)-f(y)-x+2$. Then $\frac{df}{dx}$ at $x=e$ is:

Let $f$ and $g$ be functions satisfying $f(x+y)=f(x)f(y)$,$f(1)=7$ and $g(x+y)=g(xy)$,$g(1)=1$ for all $x, y \in \mathbb{N}$. If $\sum_{x=1}^{n} \left(\frac{f(x)}{g(x)}\right) = 19607$,then $n$ is equal to:

If $f: R \rightarrow R$ is defined as $f(x+y)=f(x)+f(y)$,$\forall x, y \in R$ and $f(1)=5$,then find the value of $\sum_{r=1}^n f(r)$.

Find $\sum_{t=1}^{39} f(t)$ if $f: R \rightarrow R$ is defined as $f(x+y)=f(x)+f(y)$ for all $x, y \in R$ and $f(1)=7$.

Let $f$ be a polynomial function such that $\log_2(f(x)) = (\log_2 (2 + \frac{2}{3} + \frac{2}{9} + \dots \infty)) \cdot \log_3 (1 + \frac{f(x)}{f(1/x)}), x > 0$ and $f(6) = 37$. Then $\sum_{n=1}^{10} f(n)$ is equal to:

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