ENGLISH
REFERENCE

theta

n. C / U
C2 Proficiency US //ˈθeɪtə// UK //θˈiːtɐ// theta Informal

n. the eighth letter of the Greek alphabet. You often see it used in math to represent an angle or in science to describe specific brain waves.

n. the eighth letter of the Greek alphabet (Θ, θ). Frequently represents an unknown angle in trigonometry or denotes the sensitivity of an option's price to the passage of time in financial modeling.


SIMPLE

The teacher used the symbol theta to mark the angle in the triangle.

CONTEXTUAL

In geometry class, we learned that the sine of theta represents the ratio of the opposite side to the hypotenuse.

COMPLEX

Advanced sleep studies often monitor theta waves, which are brain patterns typically associated with deep relaxation, meditation, or the early stages of light sleep.

Usage

Uncountable when referring to the abstract concept or letter; countable when referring to specific instances or mathematical variables.

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