1. The number of intersection points between the graphs of the functions $y=\sin x$ and $y=\log _{2021}|x|$ is
A. 1284
B. 1285
C. 1286
D. 1287
Solve:
$2021=643.3 \pi$, except for the interval $(0,2 \pi)$, $y=\sin x$ and $y=\log _{2021} x$ have 2 intersection points in each interval $(2 k \pi, 2 k \pi+\pi)(1 \leqslant k \leqslant 321)$. Therefore, the number of intersection points between the graphs of $y=\sin x$ and $y=\log _{2021}|x|$ is $2 \times 643=1286$. So the answer is $C$.