<p>Okay so now I'm stuck. How in the heck do I find the 2nd derivative of -5e^3x(sin x -3 cos x). No idea what to do.</p>
<p>Still stuck on (3x-5)^4 (4x+11)^5
Is this the 1st derviative of (3x-5)^4? 4(3x-5)^3(3)
Is the 1st derivative of (4x+11)^5 5(4x+11)^4(4) </p>
<p>Then would I simplify and do the product rule?</p>
<p>no idea what -5e^3x means, but your two </p>
<p>"Is this the 1st derviative of (3x-5)^4? 4(3x-5)^3(3)
Is the 1st derivative of (4x+11)^5 5(4x+11)^4(4) "</p>
<p>are both right</p>
<p>okay that makes me happy. :)</p>
<p>If anyone can help, I'm doing the derivative of (-x^2+1)/(x^2+1)^2 and I got to (x^2+1)^2(-2x)-(-x^2+1)(2(x^2+1)(2x)/(x^2+1)^4</p>
<p>man i could so do that on paper... stupid computer...</p>
<p>(2x^5-4x^3-6x)/(x^2+1)^4 i dont think you can break it down more...</p>
<p>I got (2x(x^2-3)) / ((x^2+1)^2)</p>
<p>so you were able to factor out (x^2+1)^2?</p>
<p>okay i see what youre saying but the denominator should be (x^2+1)^3</p>
<p>so is the final answer (2x(x^2)-3)/((x^2)+1)^3)?</p>
<p>yes that's right.</p>
<p>One more question.</p>
<p>Let's say I have (3x-5)^4(80x+220)^4+(4x+11)^5*36x-60)^3 how do I finnish it? Do I use pascals triangle to multiply it out? </p>
<p>And can anyone do f'(x) of -5e^(3x)(sin x -3 cos x)? Or point me in the right direction?</p>
<p>For the second problem, use:</p>
<p>(fg)' = f'g + g'f</p>
<p>for the first one I'm going to assume you meant ( not *.</p>
<p>do the chain rule inside the product rule right? you do that to both parts then voila.</p>
<p>I have no clue about the second one.</p>
<p>Just kidding... I think that you've already found the derivative of the first one havent you?</p>
<p>2nd prob:
do what adad said: f'g +g'f (product rule)
so that's:
(-15e^3x)(sinx-3cosx) + (cosx + 3sinx)(-5e^(3x))</p>
<p>is e just a regular variable?</p>
<p>Thansk everyone for all your help! I've got them both figured out now yipee! :D...I think :confused:</p>
<p>maybe not...for the first one I'm working on the 1st derivative...and that's as far as I could get before I got stuck</p>
<p>jusgimmethegun, e is approximately 2.71828... it has some crazy calc meanings (limits or w.e) but i forget them..
anyway, the derivative of e^x is always e^x. so the derivative of -5e^3x would be -5e^3x * 3 = -15e^3x</p>
<p>i briefly remember my calc and trig teachers mentioning that, but our class seems to be moving pretty slow.. I'm getting sorta bored with this easy derivative stuff.</p>