How do I graph these two problems?

Question

y = −x2

g(x)= sqrt x-1

Answer 1

You take some values of x. Then substitute them to the equation to get the corresponding y values. Plot the points.
For instance, y = -x^2
at x = 0,
y = -0^2
y = 0
So a point on the graph is (0,0)

at x = 1,
y = -1^2
y = -1
So a point on the graph is (1,-1)

at x = -1,
y = -(-1)^2
y = -1
So a point on the graph is (-1,-1)

...and so on until you see the pattern or shape it takes, and you can draw the curve and arrowheads at each end.