Mathematics · 2020
JEE Main · 6 September 2020, Shift 1 · Q58
If f(x+y)=f(x) f(y) and Σ_x=1^∞ f(x)=2, x, y ∈ N, where N is the set of all natural numbers, then the value of (f(4))/(f(2)) is:
If $\displaystyle f(x+y)=f(x) f(y)$ and $\displaystyle \sum_{x=1}^{\infty} f(x)=2, x$, $\displaystyle y \in \mathbf{N}$, where $\displaystyle \mathbf{N}$ is the set of all natural numbers, then the value of $\displaystyle \frac{f(4)}{f(2)}$ is :
Official answer
(4)
$\displaystyle \frac{4}{9}$
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JEE Main 2020 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.