Recent content by neutron star

  1. N

    Derivative ^x, is this correct?

    Homework Statement y=\sqrt{x} * 19^x Homework Equations The Attempt at a Solution y=x^{1/2}*19^x y'=1/2x^{-1/2}*19
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    Derivative of a function, Is my answer correct?

    Ugh, it said incorrect...
  3. N

    What is the derivative of z=(te^6t + e^7t)^5?

    Homework Statement Find the derivative of the given function z=(te^6t + e^7t)^5 Homework Equations The Attempt at a Solution 5(te^6t + e^7t)^4
  4. N

    Derivative of a function, Is my answer correct?

    Homework Statement y=e^9Θsin(8Θ) Homework Equations The Attempt at a Solution dy/dΘ=e^9Θ(sin(8Θ)+8cos(8Θ))
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    Derivative, Is my answer correct?

    Homework Statement y=sin^6[SIZE="2"](4Θ) Homework Equations The Attempt at a Solution dy/d\theta=24sin^5(4\theta)cos(4\theta)
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    How in the blazes is this the derivative of f(x)?

    Homework Statement f(x)=(2x+1)^11 (5x-1)^9Homework Equations The Attempt at a Solution f'(x)=[(2x+1)^10 (5x-1)^8] * (200x+23) Where does the +23 come from, I don't get it. I get the rest.
  7. N

    Forces on an inclined plane, kinetic friction How is this wrong?

    I don't think it's possible to solve that without having a. You have: T-38sin(a)-(0.26)(N)=3.8a + 55-T=5.5a It would be 38sin(a)-(0.26)(N)+55=9.3a You can't put in the normal force because you need acceleration to solve m1gcos(a) and you can't get rid of that 38sin(a). I'm guessing...
  8. N

    Solving a Strange Derivative Problem

    Hey, thanks that was really helpful! I didn't think of dividing by t^7. That made it easy! Thank you! I'll remember this if I get another similar problem!
  9. N

    Forces on an inclined plane, kinetic friction How is this wrong?

    Homework Statement In the figure below, m1 = 3.8 kg, m2 = 5.5 kg, and the coefficient of kinetic friction between the inclined plane and the 3.8-kg block is μk = 0.26. Find the magnitude of the acceleration of the masses and the tension in the cord...
  10. N

    Graphing a Piecewise Function: Is it Continuous and Differential?

    Homework Statement This is the last of 10 calculus problems I have to do this week (besides the one I have half finished) 7/8 so far :). This problem asks if the function is continuous and differential. I don't know how to graph this though. Can somebody help explain, I only need to know how...
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    Solving a Strange Derivative Problem

    Homework Statement f(t)=\frac{t^5 + t^6 - 1}{t^7} Homework Equations The Attempt at a Solution This is different than the other problems I've been doing. My first guess would be that I would do this: f(t)=\frac{5t^4 + 6t^5}{7t^6} Is that the final answer or is there another...
  12. N

    Is This Derivative Calculation Correct?

    Homework Statement y= 4^x + 9/x^3 Homework Equations The Attempt at a Solution y'= ln(4)4^x-27x^-^4
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    Calc Tension of 2 Angles: 590-N Ball Suspended from Cords

    Wait, ok so T_{2}=T_{1}cos(50) so T_{1}sin(90)+(T_{1}cos(50))sin(50)-F_{g}=0 right? T_{1}=0.670F_{g} T_{1}=590/.670=880.597N This doesn't seem right, what did I do wrong?
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    Quick thing How did they get this?

    https://www.physicsforums.com/showthread.php?t=259689 In that thread how did the person figure out the contact force between mA and mB? I know they got the acceleration by doing F/mA+mB. But I don't get how they got the contact force, because all the blocks are equal mass. Something like...
  15. N

    Newton's second law and direction of force

    0=22.1m/s^2+2a(55.3) -110.6a=488.41m/s a=-4.416m/s 0=22.1m/s^2+(-4.416m/s)t 22.1m/s^2/4.416m/s=5.004s t=5.004s Is this right? How do I get mass from this? F=ma right, so m=F/a or 12.6=m(-4.416) or m=12.6/-4.416. But it doesn't seem to work...