The sine of an angle is defined based on the angle's position in the unit circle. The sine of 0 degrees (or 0 radians) is 0.
However, it's unclear what you mean by "when 0=90." If you're equating 0 to 90, that doesn't align with standard mathematical definitions or conventions.
To clarify:
- \(\sin(0^\circ) = 0\)
- \(\sin(90^\circ) = 1\)
In essence, \(\sin(0)\) remains \(0\) regardless of any incorrect equation like \(0=90\). If you need help with something specific or a different angle, please feel free to ask!