今天,小精灵将带大家认识一种特殊的函数.它会是什么呢?请看小明与小精灵的对话.小明:什么样的函数是一次函数呢?小精灵:若两个变量x,y间的关系可以表示成y=kx+b(k,b为常数,且k≠0)的形式,则称y是x的一次函数(通过简单的变形可知,若y是x的一次函数,则x也是y的一次函数).特别地,当b=0时,关系式变为y=kx(k是常数,且k≠0),此时称y是x的正比例函数. Today, the elf will bring you to know a special function. What will it do? Look at the dialogue between Xiaoming and elf Xiao Ming: What kind of function is a function? Elf: If two variables x, y The relationship between y = kx + b (k, b is a constant, and k ≠ 0), then said that y is a linear function of x (through a simple deformation, we can see that if y is a linear function of x, then the relationship between x is also a linear function of y) .In particular, when b = 0, the relation becomes y = kx (k is a constant and k ≠ 0), in which case y is called a proportional function of x.