ok, I am completely at a loss - I don't even know where to begin.
for (a): I should find the slope of T - but I have no idea how - could I make a triangle and solve for the hyp? so would it be like
and then I am at a complete loss, partially because the given diagram is so confusing ... any help would be greatly welcomed
For part c, you use the tangent line at to approximate the value of the function at . In the drawing you have, this approximation is given by the length of . But the formula for this approximation is , which simplifies to in this case.
For part d, this is simply . It doesn't help you a whole lot except that as h approaches zero, this is the derivation of the derivative of at a.