Is this function linear or nonlinear? y=1x

Linear means that the exponent is 1
y=1x^1
yes
true

A linear function is in the form y = mx + b or f(x) = mx + b, where m is the slope or rate of change and b is the y-intercept or where the graph of the line crosses the y axis.  This function is linear, this is because y = 1x is in the form y = mx, there the + b is just + 0 since there is nothing adding into it.