1)consider f(x)= 2- x for x<=0 and k-x^2 for x>0. For which values of k belonging to R has f(x) got a point of local minimum at x=0?

2) If y= f(x) has a point of global minimum at x=6, which of the following functions has certainly got a point of global max at x=0? The possible answers are a) y= -6f(x); b)y=-f(6x); c)y=f(x+6); d)y= -f(x+6) I feel like crying...though they're stupid and basical things...help me please..