3. Find the linear approximation to the following functions about x=0: (a) f(x) = (1+x) (b) f(x) = (1+x) (c) f(x) = (1-1)1/4 4. Determine the values of x at which each of the functions defined by the following formulas is continuous: (a) EC 72+ 1 (b) 18-3x- +1 x2+2x-2 (c ) Vat (r+2)3/2 5. Use L'Hopital rule to find the following Limits: Inc-r+1 (a) lime-+1 (x-1)' (b) lime-1 2 In 7+1 41+4 (c) lime-1 1-rtli 6. Find the intervals where the following functions are increasing: (a) y = (Inx)2 - 4 (b) y = In(e +ex) (c)y=x-In(x- + 2)