(10) If $0<x \leqslant 1, a=\left(\frac{\sin x}{x}\right)^{2}, b=\frac{\sin x}{x}, c=\frac{\sin x^{2}}{x^{2}}$, then the size relationship of $a$, $b$, and $c$ is $\qquad$ .
(10) $a<b \leqslant c$ Hint: When $0<x \leqslant 1<\frac{\pi}{2}$, $\sin x<x$, then $0<\frac{\sin x}{x}<1$, so $\left(\frac{\sin x}{x}\right)^{2}<\frac{\sin x}{x}$. Also, since $y=\frac{\sin x}{x}$ is a decreasing function on $(0,1]$, $\frac{\sin x}{x}<\frac{\sin x^{2}}{x^{2}}$, but when $x=1$, $b=c$.