\Denition" A: A tangent to a curve can only meet the curve at one point.?

Question

\Denition" B: A tangent to a curve can only meet the curve at one point,
and the curve must lie entirely to one side of the tangent.
\Denition" C: A tangent to a curve can only meet the curve at one point,
and the may not bisect the curve at that point.

Can anyone give me example of functions that disprove these "definitions"

Thank you any help appreciated

Answer 1

The line y = 1 and y = -1 are tangents to sine and cosine when sin (x) = 1 or -1 and cos (x) = 1 or -1

Thats all I can think of...