A secant is a straight line connecting two points on a curve; therefore, the first thing we need to do is solve for the y values at the two given values of x:
-2log(1)+3 = 3
-2log(2)+3 = 2.4
Therefore, the two points are (1,3) and (2,2.4).
Slope = rise/run:
Therefore, the slope of the secant line through the points on the curve at x=1 and x=2 is -0.6.