Calc AB Exam--How'd you do?

<p>gandalf that isnt what my teacher got.</p>

<p>apparently, y = ln lxl - 1, this answer is wrong</p>

<p>based on your eq., dy/dx =1/x </p>

<p>if you sub x=2, then dy/dx = 1/2, y=ln2-1</p>

<p>then you sub y=ln2-1 into the original dy/dx, which would give you dy/dx = ln2/2<------not equal to what you assumed</p>

<p>yeah i mistyped it, she said y = -2 lxl - 1</p>

<p>oh, yep! that's what my teacher said too.. I forgot the absolute sign. lol</p>

<p>wait...is it -2x-1? or the absolute value of x?</p>

<p>should you even have the absolute value sign?</p>

<p>caus f(-1)=1</p>

<p>yeah the absolute value sign is needed. My teacher said you will only lose one point if you don't have it though.</p>

<p>yep, you definitely need an absolute sign</p>

<p>looking over my test again, i missed 1b and 1c, i seperated variables correctly for 5b and got the right domain but i screwed up the equation so im thinking 2-3/6 on that? And then I may have screwed up 3C. Everything else was right though. Maybe a 4?</p>

<p>me too lol. Reckon we'd lost a point for that?</p>

<p>if you have the absolute value sign then the f(-1)=1 doesn't work.</p>

<p>is the domain all real #'s?</p>

<p>how many for total for the free response? how may points for each section? Thanks.</p>

<p>What was its domain?</p>

<p>yes the domain is all reals</p>

<p>9 points per problem/ 54 total</p>

<p>point breakdown for 5b:</p>

<p>1 point for seperating variables(must seperate variables or you get 0 points for the problem).</p>

<p>1 point for showing that an integral needs to be taken</p>

<p>1 point for finding C</p>

<p>1 point for getting the correct equation</p>

<p>1 point for the domain </p>

<p>1 point uses initial condition </p>

<p>part A is 3 points I believe</p>

<p>if you have the absolute value sign then the f(-1)=1 doesn't work</p>

<p>looking at past point breakdowns, I think I got:</p>

<p>4 points part 1</p>

<p>9 points part 2</p>

<p>6-7 points part 3</p>

<p>9 points part 4</p>

<p>5-6 points part 5</p>

<p>9 points part 6</p>

<p>The grading seems pretty generous.</p>

<p>dang...missed one there...no abs sign for me.
also missed 1 point for 1c
so i got 8s on 1 and 5, 8-9s (maybe) on 6,4,2..i think I messed up 3...</p>

<p>what did everyone get for #3?</p>

<p>if you have the absolute value sign then the f(-1)=1 doesn't work.</p>

<p>Ryan...can you help me with this?</p>

<p>i don't really know how to explain the problem, but my teacher said you need that absolute value sign. Perhaps someone else can explain it?</p>

<p>yeah the abs sign confuses me too...are you sure that's necessary?</p>

<p>also...any math geniuses wanna post answers for 3?</p>

<p>-2x-1, x<0
2x-1, X>0</p>

<p>Clear?</p>

<p>Which part of 3? All of them or just one part?</p>