Question

what functions are second derivative of itself? what functions are negative second derivative?

Answer 1

exponential function are second derivative of itself

Answer 2

\[\frac{ d(e^x) }{ dt }=e^x\]

Answer 3

yup

Answer 4

trig functions or negative second derivatives of themselves

Answer 5

\[{d^2 \over dx^2 } \sin x = - sinx \]