准线

Traditional form:

準線

Pinyin (reading):

zhǔnxiàn

Definitions:

• directrix line of a parabola
• guide line

Characters:

• 准 - standard, accurate; to permit, to approve, to allow
• 线 - line, thread, wire; clue, trail

Traditional characters:

• 準 - standard, accurate; to permit, to approve, to allow
• 線 - line, thread, wire; clue, trail