R := 30*(int(-x^5+x^4, x = 0 .. exp(-lambda*t))):r := factor(-(diff(R, t))/R):
plot3d(R, lambda = 0 .. .1, t = 0 .. 50, font = [aexs, "Time New Roman", 12]);
plot3d(r, lambda = 0 .. .1, t = 0 .. 60, font = [aexs, "Time New Roman", 12]);
我在这个吧发过一个作图问题征集帖,以后如果你还有问题可以到那个帖子下面留言评论就好了