α=135°+k*360°=135°+2k*180°=135°+(2k+1)*180°-180°=(2k+1)*180°-45°,
α=k*360°-45°=2k*180°-45°
2k是偶数,2k+1是奇数,故合并后是α=k*180-45°,k∈Z
α=135°+k*360°=135°+2k*180°=135°+(2k+1)*180°-180°=(2k+1)*180°-45°,
α=k*360°-45°=2k*180°-45°
2k是偶数,2k+1是奇数,故合并后是α=k*180-45°,k∈Z