Mathematics · 2019
JEE Main · 12 January 2019, Shift 1 · Q75
Let f and g be continuous functions on [0, a] such that f(x)=f( a -x) and g(x)+g( a -x)=4, then ∫_0^a f(x) g(x) d x is equal to:
Let $\displaystyle f$ and $\displaystyle g$ be continuous functions on [$\displaystyle 0$, a] such that $\displaystyle f(x)=f(\mathrm{a}-x)$ and $\displaystyle g(x)+g(\mathrm{a}-x)=4$, then $\displaystyle \int_0^{\mathrm{a}} f(x) g(x) d x$ is equal to :
Official answer
(2)
$\displaystyle 2 \int_0^{\mathrm{a}} f(x) d x$
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JEE Main 2019 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.