Hint: Is something is continuous then it means that all parts of the graph will match up (i.e. there will be no sudden jumps).
As a starting hint this means that cx^2 = 4 when x = 1.
Since you're asked to make h(x) continuous, and not differentiable, it seems to me all you need is to make the three expressions equal to four at x = 1. That makes c = 4 and m = 5.
The first and third expressions are not defined at x = 1, but they will approach 4 as x "goes to 1".