Slope of tangent line Given the function $f(x)=1-\cos x$ and the points $A(\pi / 2, f(\pi / 2)), B(\pi / 2+0.05, f(\pi / 2+0.05)),$ $C(\pi / 2+0.5, f(\pi / 2+0.5)),$ and $D(\pi, f(\pi))$ (sce figure), find the slopes of the secant lines through $A$ and $D, A$ and $C,$ and $A$ and $B$. Use your calculations to make a conjecture about the slope of the line tangent to the graph of $f$ at $x=\pi / 2.$
(GRAPH CAN'T COPY)