(b)
(c)(d)(a) At  (−1,8),     so  the tangent line    is  y   −   8   =   5(x −   (−1)).
Therefore   f   (x) ≈   8   +   5(x +   1).
f   (3) ≈   8   +   5(0 +   1)  =   13.
At  (−1,8),     For Δx  =   0.5,    Δy  =   0.5(5)  =   2.5,    so  move    to
(−1 +   0.5,    8   +   2.5)    =   (−0.5,10.5).
At  (−0.5,10.5),        For Δx  =   0.5,    Δy  =   0.5(8)=   4,  so  move    to  (−0.5   +   0.5,    10.5    +   4).
Thus    f   (0) ≈   14.5.