>>13643702I get that, but say ? represents an angle in radians and ? a corresponding angle in degrees,
cos(?) = cos(180?/pi)
The conversion function r(?) is a linear function of ?, so when differentiated,
y" + ay = 0
still holds true no matter which unit system you use. What the constant of 'a' is depends on whether you let ? equal some function of ? or vice versa. a would still be 1 if cos(t) was defined for t degrees, and then cos(t (rad)) would be equal to cos(180t/pi). It's arbitrary.
