[填空题]
Consider the graph o,jn 2llkemk- v :-7)bmtby+sk f the ve .vdd 5zf,v:function f(x)= -x$^3$ +3x$^2$ +1.
1.Label the local minimum as A on the graph.
2.Label the local maximum as B on the graph.
3.Write down the interval where f′(x)>0.a , b= .
4.Draw the tangent to the curve at x=−1 on the graph. we get the tangent passes through the coordinate (- , ) and is parallel to the graph at this point.
5.Write down the equation of the tangent at x=−1.
Hence, the equation of the tangent at x=−1 is y=-ax-b, a= , b= .
