The trigonometric function that is odd is the sine function, and it is because pf how it is defined.
We define an odd function as a function that has the next property.
f(-x) = -f(x)
So we need to find a trigonometric function with this property and is rater easy to know that it is the sine function, because:
Sin(-x) = -Sin(x)
This happens because the sine function measures the vertical distance to the endpoint of an angle x, and when x (an angle) becomes negative, the endpoint is below the horizontal axis, thus the outcome is reflected from the positive angle, but with opposite sign.
If you want to learn more about trigonometry, you can read:
https://brainly.com/question/8120556
