100分求一道数学题,After t years the population of a certain town is P(t) = 50+5t thousand people.A populationP has an associated CO2 level,C(P) = (根号下（P2 + 1）)/2.After 2 years,the rate at which CO2 level is changing with respect to t

100分求一道数学题,After t years the population of a certain town is P(t) = 50+5t thousand people.A populationP has an associated CO2 level,C(P) = (根号下（P2 + 1）)/2.After 2 years,the rate at which CO2 level is changing with respect to t 一道高数题 x=te^-t+1 y=(2t-t^2)*e^-t 求 d^2y/dx^2做道高等数学题啊 一道log数学题R=100e^-0.0004279t t=10000求R的值 一道数学题t 一道数学题t 帮算一道数学题,100分! 100分求一道数学题,Find an equation for the tangent line to the curve x^2y + xy^3 = 2 at the point (1; 1). 200分一道数学题 100分求一道数学题y = cos x; x区间[0, 4派]; a = 0.5当y=a时,x=多少 应该有4个值当y>a时,x的区间当y 100分!求一道不等式数学题的解法x,y,z属于全体正实数已知 x+y+z=1证明:z/(x^2+1) + y/(y^2+1) +x/(z^2+1) 100分求一道数学题 求高手解个过程Determine where the graphs of the equations x+4y=3 and 2x-6y=8 intersect答案为（25/7,-1/7）,求过程 100分求一道数学题ln x = 3 − ln(x + 2) x等于多少 一道初二的有关平方根的数学题,已知9-√ 11与9+√ 11的小数部分分别是x,y,求x+y的值. 一道昨天月考数学题 想知道对错 若y=（x-1）²+1,当x∈【t,t+1】的最小值为g（t）,求函数g（t）及t∈[-3,-2]的最值 一道初三数学题 求大神 急需!求过程 不要方法T.T最好详细一点 谢谢. 一道30分的数学题 一道数学题求解释 一道数学题求面积