<p>IceQube: This may be wrong, but I don’t think that is correct. A horizontal tangent line has a slope of 0, which does not make the function un-differentiable.</p>
<p>What I would do for jspeed’s problem is take the derivative of (x+2)^1/3 - 1, getting:</p>
<p>1/(3(x+2)^-2/3), a fraction with the variable in the denominator. When x=-2, the denominator is zero, so the derivative is undefined and the equation is un-differentiable at that point.</p>
<p>I’m using Barrons and Princeton both for Calc. They’re good supplements to the classwork.</p>
<p>Ok well my calc teacher pushed the quiz to tomorrow. I asked him about that question and he just told me for those to just graph them and for the one I gave you guys, it had a vertical tangent at x=-2 and therefore it wasn’t differentiable at that point</p>
<p>I have midterm finals tomorrow in this class. Wish me luck!</p>
<p>Good luck! You can do it!</p>
<p>Ugh. I think I failed. I hate it when teachers give us questions we haven’t even learned how to do. I guessed on 7 multiple choice problems and on one of the free response sections I just crossed everything out and wrote “ignore the x’s”. I feel like crying. Everyone else thought it was impossible too. ANd our teacher doesn’t curve :(</p>
<p>So how are you guys doing in your class so far? I got 100 on my derivatives quiz (CSAmath, you’re a beast!) Still got another half chapter on applications of derivatives and such. What are you guys on and do you know where the BC class is at?</p>
<p>I’m in AB/BC and we just finished Riemann sums (Intro to definite Integrals) two weeks ago before fall break and in 2 days school will start again and we will begin those definite integrals.</p>
<p>I’m in AB/BC as well. In BC we finished doing polar coordinates and graphing and finding the derivatives of polars. In AB we finished doing all the derivative rules and are now doing logs/natural logs. Got a 102 on the last test.</p>
<p>Feel weird saying it, but my AB class is moving pretty slow in my opinion and isn’t nearly as challenging as BC.</p>
<p>Is anyone else finding Calc strangely easier than all other math courses? We’ve covered limits and continuity already, and now we’re going into derivatives (including secant/tangent lines algebraically). It seems to me like the actual Calc concepts are very easy; it’s just remembering the algebra at this point.</p>
<p>Hey guys!! I am making a The Chain Rule/Higher order of Derviatives + related rates study guide. (My teacher changed up the curriculum a bit… normally related rates would be much later. But he taught it to us) Expect the guide up tonight - early friday</p>
<p>Can anyone help me out with taking derivatives of inverse trigonometric functions with two variables?</p>
<p>^ Sure what kind of help do you want? WIth specific problems?</p>
<p>nvm I got help from my friend in class 
thanks anyway</p>
<p>The one neat thing that I always try to point out when working with inverse trig derivative rules is that you don’t actually need to memorize them… if you’re willing to take the time to re-derive them on the fly. Every once in awhile, inverse trig derivatives rear their ugly head for a significant portion of the test, but not most years.</p>
<p>That being said, suppose you’re sitting there mid-test having a coronary because you forgot the derivative of y = Arctan x. You can use implicit differentiation to get your solution…</p>
<p>y = Arctan x
x = tan y
1 = sec^2 y * y’
y’ = 1/(sec^2 y) = (cos^2 y) = cos^2 (Arctan x)</p>
<p>Set up a right triangle where the opposite side is x and the adjacent is 1 (since the angle x = x/1). Then the hypotenuse is sqrt(1 + x^2). Cosine of this angle is adjacent/hypotenuse = 1/(sqrt (1 + x^2)). Squaring this yields 1/(1 + x^2), which is the formula you normally are asked to memorize!</p>
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<p>Introducing a second variable into these questions (i.e. d/dx[Arctan (kt)] type problems) usually have one of two types of ingredients:</p>
<p>(1) The second variable isn’t really a variable but a constant, but just unknown, in which case you’d treat it just like any other constant like 2.</p>
<p>(2) The second variable really is a variable, in which case, you’d need the Product Rule when taking the derivative of the inside piece of that Arctan function.</p>
<p>Why is optimization so hard? :(</p>
<p>Optimization is really just an “absolute min/max question” combined with word problems combined with “finding the domain and range” for the endpoints. Many people don’t like any one of those, let alone all three together.</p>
<p>Hey everyone, what are you learning in your class now? I’m not in AP Calculus AB though, I’m taking Calc I in my local CC. Now my professor started on antiderivatives. I’m doing fine in my class, the grade is mostly based on tests and of the two tests I have taken, I got A in both. Then again, my professor lets my class use notes on exam… (but only 1/4 of the class gets As) And my class size is really small, back in August it was 42, now only half that much.</p>
<p>And as joshmay94 stated, I do find most Calculus concepts understandable, I sometimes have difficulty in the algebra involved. </p>
<p>And yeah, I know AB covers some stuff in Calc II so I’ll need to self-study after the semester is up.</p>
<p>Yeah I’m liking Calc so far. We’ve done a lot and my teacher is the best in the school. We’re up to Rectilinear motion. We just took a test on applications of the derivative(rel and abs min/max).</p>
<p>In BC, we just started finding the area under functions using the rectangle method, and the integral method.</p>