For a function of two variables z=f(x,y), the gradient is the two-dimensional vector <f_x(x,y),f_y(x,y)>. This definition generalizes in a natural way to functions of more than three variables. For the function z=f(x,y)=4x^2+y^2.
By this definition, about 10% of people who smoke marijuana become addicted to it. (More on Time.com: PHOTOS â Cannabis Conventions). However, nonspecialists (including many doctors) still tend to use an older perspective, now seen as outdated by experts.
Compared to other substances, marijuana is not very addicting. It is estimated that 32% of tobacco users will become addicted, 23% of heroin users, 17% of cocaine users, and 15% of alcohol users.Cocaine and heroin are more physically harmful and nicotine is much more addictive.It is much harder to quit smoking cigarettes than it is to quit smoking pot.Recreational users of the past are often compared to todays smokers. The smokers, the times and the pot are all different.ocaine and heroin are more physically harmful and nicotine is much more addictive. It is much harder to quit smoking cigarettes than it is to quit smoking pot. Recreational users of the past are often compared to todays smokers. The smokers, the times and the pot are all different.