A picture of a woman with a bow and a glowing arrowA picture of a woman with a bow and a glowing arrow
Abstract lines of different colors and bright shadesAbstract lines of different colors and bright shades
Abstract fish made of glowing lines on a light backgroundAbstract fish made of glowing lines on a light background
В математике: всякая непрямая линия. Кривая линия, изображающая рост или падение чего-н. в развитии какого-н. процесса.