<p>Hi guys, do you know the answer to #18 on page 400?</p>
<p>I can't see how III. is one of the possibilites.</p>
<p>ok well (a,b) a is the location on the x axis and b is the location on the y axis </p>
<p>I. must be true because there is a limit at x=4
II. is not true because the point could be (3,almost 4) or some decimal answer where the Y is greater
III. is true because the graph f(a) is the y=f(x) they have the arrow to up there which is the boundary to the shaded region </p>
<p>so the answer is D I and III only</p>
<p>Your explanation for III is kind of confusion so I’ll word it a little better:</p>
<p>Since f(a) is the function itself, b must be <= f(a) because that graph defines the shaded region.</p>
<p>Thanks for clearing that up.</p>
<p>So basically, f(a) = b? </p>
<p>since f(a) basically means f(x)?</p>
<p>f(a) can be equal to b, but not always. For example, the point (3,1) is in the shaded region, but f(3) = 4. That’s why it states b <= f(a) instead of just b = f(a).</p>
<p>“f(a) can be equal to b, but not always”
ok i sort of get it</p>
<p>so is there some easy trick when looking at these type of problems?
sorry my my imcompetence lol</p>
<p>You just have to think about creatively, and with common sense. Look at it from a picture term instead of math term. Could you think of any ‘b’ above the line but under the shaded region? I don’t think so :p</p>
<p>K thanks :]]]]]]]]]]]]]]</p>