The picture should look like figure 2 on page 159. This is called an indifference curve because the consumer is indifferent to any combination of A and B on the curve. Characteristics of Indifference curves. Indifference curves are negatively sloped, downward sloping. Explain why indifference curves are negatively sloped.
Indifference curves are convex to the origin.
Thus if you are looking at the curve from the origin it will be bowed in. Just as an aside a production possibility curve was bowed out from the origin. Now what is the slope of the indifference curve telling us. It is telling us how much of A we are willing to substitute to get more of good B in order to maintain the same level of satisfaction. Thus the marginal rate of substitution is diminishing.