y = sin ( π x 2 ) y = x {\displaystyle {\begin{aligned}&\color {red}\mathbf {y=\sin({\frac {\pi x}{2}})} &\color {royalblue}\mathbf {y=x} \\\end{aligned}}}
sin ( x π 2 ) = x x = 0 x = 1 {\displaystyle {\begin{aligned}\sin({\frac {x\pi }{2}})&=xx&=0\\x&=1\\\end{aligned}}}
