Related Clues:

• ___ qua non
• Trig. function
• Kind of curve, in math
• Trig function
• Trig ratio
• Kind of curve
• Kind of wave
• Ratio of AB to BC, say
• Fourier series function
• Math ratio
• Trig. ratio
• Trigonometry ratio
• Geometry calculation
• Trig figure
• Cosecant's reciprocal