Which of the following functions has a rate of change that stays the same?

y=x^2-5x-14
y=19x-10
y=5^x
y=0.03x^2+11x+1

For polynomials, if we say of "rate of change", we are talking about the slope of the tangent line. That is the value of dy/dx or the differential of y in terms of x. From the given choices, the answer would be the second choice, y = 19x - 10. This is because dy/dx in this item is essentially equal to 19 which is a constant.