1.Find an equation for the tangent line to the graph of f(x)=x2 +4 at (-4, 20)

2.Find an equation for the tangent line to the graph of f(x) = -x3 at (-2, 8)

3.Piecewise function: f(x) = { x2 + 6 for x <= 3 }

3x + 6 for x > 3

is f continuous at x=3?

is f differentiable at x=3?