The point P(1,0) lies on the curve ( y = sin ( x/13 ) ). If Q is the point ( (x, sin ( x/13 )) ), find the slope of the secant line PQ for various values of x.
a) Slope at x = 2: [value]
b) Slope at x = 1.5: [value]
c) Slope at x = 1.4: [value]
d) Slope at x = 1.3: [value]