Recent content by josh_123

  1. J

    Finding derivative and solve for t

    Hello everyone, so I redo the derivative a(t)= -2t(t2+4)2-2(t2+4)(2t)(-t2+4)/ (t2+4)4 does that look about right?
  2. J

    Finding derivative and solve for t

    oh okay here is the step a(t)= -2t(t^2+4)^2 is the part f'g and then subtract the g'f part I used the chain rule to find g' which is 2t(2t^2+8)<----g'(t^2+4)^2<-----f and divide by g^2 which is( (t^2+4)^2)^2) which clean up to be equal (t^2+4)^4 and that why I got...
  3. J

    Finding derivative and solve for t

    Hello there, the function is v(t)=-t2+4/(t2+4)2 and to find the derivative I'm suppose to find v'(t) or a(t) The reason why I have to set the second derivative to 0 so that I could find the point at which the function is concave up or down. (those are called stationary points?) I find the...
  4. J

    Finding derivative and solve for t

    Hello so I'm supposed to find the derivative of (-t2+4)/(t2+4)2 and using the quotient rule + the chain rule I got this mess: dy/dx= -2t(t^2+4)^2-2t(2t2+8)(t2+4)2/ (t2+4)4 and now I have to set that whole thing to 0. I know the numerator must be equal to 0 which mean that one of the...
  5. J

    Analysis of Functions I: increase, decrease, and concavity

    Actually I finished this before checking back haha. Please delete this post
  6. J

    Analysis of Functions I: increase, decrease, and concavity

    Hello I need help with these problems. The direction said a. find the intervals on which f is increasing, b. the intervals on which f is decreasing, c. the open intervals on which f is concave up, d. the open intervals on which f is concave down and e. the x-cordincates of all inflection...
  7. J

    Finding the derivative of trig function

    thank you what about the other two?
  8. J

    Instantaneous rates of change. Exponential growth and Decay

    The equation I used for these are: If N=Noekt then DN/Dt=N0kekt so the two problems I have trouble with is A radioactive substance has a decay constant (k) of -.0539 per year. If 371 grams of the material is initially present, what is the instaneous rate of change of the substance at times...
  9. J

    Finding the derivative of trig function

    Find dy/dx of these functions: 1. y=sin-1(1/3x) dy/dx=1/(√1-(1/3x)2 (1/3) dy/dx=1/(3√1-(1/9x2) However the book answer is 1/√9-x2). How did they get this? 2. y=sin-1(1/x) dy/dx=1/√1-(1/x)2 (-1/x2) If i tried to simplified it by multiply it by x^2/x^2then dy/dx= -x^2/x4√x2-1 which...
  10. J

    Derivatives of the Natural Exponential and logarithmic Functions

    1. Hello there, I have a few questions on the derivative homework that I did but not sure if it's right or not. These are difficult and my teacher doesn't go over all of them so I don't know if it is right or not. Please help me so I can understand the concepts before the upcoming test. 1...
  11. J

    Finding derivative of log and lnx. Please help Need help before test

    I retry the 2nd one and here is the final answer (with your instructions =D) dy/dx=1[log2(x^2-2x)]3 + 3[log2(x^2-2x)]2[(ln(x^2-2x)/ln2)(x)] dy/dx=[log2(x^2-2x)]3 + 3x[log2(x^2-2x)]2 ((ln(x^2-2x)/ln2) Is this right?:confused: and I'm sorry I typed the last one wrong. It suppose to be...
  12. J

    Finding derivative of log and lnx. Please help Need help before test

    Hello, thank you so much for your help. ~I re-try the first one and I got: 2(sinlnx)(1/x)(cos(lnx)). Can you tell me if this is the right answer? ~the second one I retry and got dy/dx=1 [log2 (x2-2x)]3 + [3log2(x^2-2x)]2 (x) so to simplified it is : [log2(x2-2x)]3+ x[3log2(x^2-2x)]2~Can...
  13. J

    Finding derivative of log and lnx. Please help Need help before test

    I need help in finding dy/dx or the derivative of these function: 1. y=sin^2(lnx) so d/dx[sin^2(lnx)] I tried following this model of sin^x=(sinx)^2 so d/dx[(sinlnx)^2)]. Then use the chain rule of dy/dx= f'g(g') which is 2(sinlnx)(cos1/x) but I don't think that is right so can you please tell...
  14. J

    Use matrices to solve the problem

    hi is anyone have an answer?I really need help
  15. J

    Use matrices to solve the problem

    Here is the problem: Use matrices to solve the following problems:Show your matrices that you use as well as your solutions. Classroom Example: The three major companies are coca cola, pepsi and 7up. Coca-Cola has a 40% share of the soda market, Pepsi has 40% of the soda market and 7up...
Back
Top