[填空题]
The concentration in 6e yn7n6k s6rhu ;hmi,mg of a certain medicine t hf,w g:jvwicx j 6,j*k/ours after administration can be modeled by C(t) = 1jg*c /,iwjwj, 6f xkv:000te$^{-1.25t}$ , t≥0.
1.Find the rate of change of the concentration with respect to time.
C'(t) = 1000e$^{-1.25t}(a-b1.25t)$ , a= , b= .
2.Find the value of t when the rate of change of C is zero.
t= .
3.Determine if the time found in part (b) is a local minima or maxima for C. Justify your answer.
