MathDB

For a nonnegative integer

n

and a strictly increasing sequence of real numbers

t_0, t_1, \ldots, t_n

, let

f(t)

be the corresponding real-valued function defined for

t \geq t_0

by the following properties: (a)

f(t)

is continuous for

t \geq t_0

, and is twice differentiable for all

t>t_0

other than

t_1, \ldots, t_n

; (b)

f\left(t_0\right)=1 / 2

; (c)

\lim _{t \rightarrow t_k^{+}} f^{\prime}(t)=0

for

0 \leq k \leq n

; (d) For

0 \leq k \leq n-1

, we have

f^{\prime \prime}(t)=k+1

when

t_k<t<t_{k+1}

, and

f^{\prime \prime}(t)=n+1

when

t>t_n

. Considering all choices of

n

and

t_0, t_1, \ldots, t_n

such that

t_k \geq t_{k-1}+1

for

1 \leq k \leq n

, what is the least possible value of

T

for which

f\left(t_0+T\right)=2023

B4