If $f(x)=\frac{\cos x}{\sin ^2 x+\cos ^4 x}$, for $x \in R$, then $f(2002)$ is equal to
If $f(x)=\frac{\cos x}{\sin ^2 x+\cos ^4 x}$, for $x \in R$, then $f(2002)$ is equal to
- $1$
- $2$
- $3$
- $4$
Solution
We have,
$
f(x)=\frac{\cos ^2 x+\sin ^4 x}{\sin ^2 x+\cos ^4 x}
$
$\begin{aligned} & =\frac{1-\sin ^2 x+\sin ^4 x}{1-\cos ^2 x+\cos ^4 x} \\ & =\frac{1-\sin ^2 x\left(1-\sin ^2 x\right)}{1-\cos ^2 x\left(1-\cos ^2 x\right)} \\ & =\frac{1-\sin ^2 x \cos ^2 x}{1-\cos ^2 x \sin ^2 x}=1 \\ \therefore \quad f(2002) & =1\end{aligned}$
Asked in: AP EAMCET 2002
Practice more Functions questions on Aicharya