4. The point P(0.5, 0) lies on the curve y - COS TIX. (a) If Q is the point (x, coS Tx), use your calculator to find the slope of the secant line PQ (correct to six decimal places) for the following values of x: (i) 0 (ii) 0.4 (iii) 0.49 (iv) 0.499 (v) 1 (vi) 0.6 ( vii) 0.51 (viii) 0.501