Which of the following describes a likely relationship between a country's population growth and its water supply? (3 points) As population increases, people must pump more water into aquifers.
As population increases, people must use more water to irrigate crops.
As population increases, people must treat more gray and black water.
I only
II only
III only
I and II only
II and III only

Ithink the answer is d

You need to figure out at which x-value does the graph has a tangent line slope of -1.remember, the derivative is the slope of the tangent line. so find the derivative function and set it to equal -1 to find the x-value that will have a tangent line slope of 0.differentiate with the chain rule.    set the derivative to equal -1 and solve for x.      take log base 10 of both sides. also recall that  .    so the x-coord of the point of tangency is .the y-coordinate of this point of tangency can be calculated using the original function:     using point-slope form, the equation of the tangent line is      the x-intercept of this tangent line is when the graph is at y=0.    this rounds off to  .choice c.