Mathematics · 2019
JEE Main · 11 January 2019, Shift 1 · Q88
Let f_k (x)=1/(k)( sin^k x+ cos^k x) for k =1,2,3, …. Then for all x ∈ R, the value of f_4(x)-f_6(x) is equal to:
Let $\displaystyle f_{\mathrm{k}}(x)=\frac{1}{\mathrm{k}}\left(\sin ^{\mathrm{k}} x+\cos ^{\mathrm{k}} x\right) \quad$ for
$\displaystyle \mathrm{k}=1,2,3, \ldots$. Then for all $\displaystyle x \in \mathbf{R}$, the value of $\displaystyle f_4(x)-f_6(x)$ is equal to :
Official answer
(1)
$\displaystyle \frac{1}{12}$
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JEE Main 2019 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.