Recent content by opus

  1. opus

    Using the Law of Sines - Getting a Domain Error on my Calculator

    Thanks all! I’m about to take an exam so I’ll come back to this when I get home!
  2. opus

    Using the Law of Sines - Getting a Domain Error on my Calculator

    So we'd like to find leg C. But we can't use Law of Cosines yet so we will use Law of Sines. We can easily find the length of A and this is ##\sqrt{13}##. With some geometry we can see that ##\angle a = 53.1##. We can now use Law of sines. $$\frac{\sin(a)}{A} = \frac{\sin(b)}{B}$$ We want to...
  3. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    For reference, these points of intersection are all solutions to the equation (in other words, when my two vectors are perpendicular). But am I correct if I say that there is no explicit way to state every single solution here?
  4. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    If we look at the trigonometric equation in a vacuum, I can see how we can say that the solutions tend to ##n\pi##. I also can see that there are an infinite amount of solutions. But the original question is to find when the vectors are perpendicular (that is, when is cos = 0). So it seems I...
  5. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    Ok now I definitely can see that. So then would it be satisfactory to say that, with respect to the original problem, ##\cos(\theta) = 0## when t = 0 and when ##t = (n + \frac{1}{2})\pi## where n is an integer?
  6. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    Im not seeing that at all. For example at n = 1, we should have ##\frac{3\pi}{2}## its a little over ##\frac{\pi}{4}## as I'm looking at Desmos for better accuracy.
  7. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    Yes indeed, I was trying to graph one function instead of two separate ones not sure why. I've got the sketch now though. Alright I think there are infinite solutions to ##\tan(t) = \sqrt{\frac{1}{t}}## and I see this with the sketch. Now, these values are not pretty so I'm not sure how to...
  8. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    Ok so spent some time trying to graph this thing and wasnt having much luck. Went to Desmos to have a look and it's an absolute nightmare of a graph. Also tried to express ##\tan(t) = \sqrt{\frac{1}{t}}## a different way but of course that gave me the same thing in Desmos. This is assuming...
  9. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    Wouldn't I run into problems if I did the following to get tan(t)? : $$t\sin^2(t) = \cos^2(t)$$ $$t\tan^2(t) = 1$$ $$\tan(t) = \sqrt{\frac{1}{t}}$$ The problems I see with this are dividing by ##\cos^2(t)## as it could be zero. Also, t in the denominator on the final line could be zero as well.
  10. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    Ok wow I guess I should rephrase my question then, since I thought this was going to be a simplish trig equation. This trig equation is a part of a bigger problem where I am trying to find out what values of t make a position vector and an acceleration vector perpendicular. I've attached a pic...
  11. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    You're talkinga bout the variable t preceding the second term, correct?
  12. opus

    Trig Equation — help to solve please: 0=cos^2(t)−t sin^2(t)

    I'd like to solve ##0 = \cos^2(t) - t\sin^2(t)## but it's been forever since I've done some trig and I'm real rusty. I've tried rewriting terms using identities such as ##\sin^2(t) = 1 - \cos^2(t)## but not getting anything helpful. Can I get a point in the right direction?
  13. opus

    Mult Variate Calc: Proof for N(t) vector

    Thanks Mark that is more clear! Going to keep plugging at this to see what I can get
  14. opus

    Mult Variate Calc: Proof for N(t) vector

    Ok so ##\vec{T}(t)##, ##\vec{N}(t)##, and ##\vec{a}_{v\perp}## arent ever mentioned in any previous problem for this homework, but in the text they are given as: ##\vec{T}(t) = \frac{\vec{v}(t)}{v(t)}## so a unit vector in the direction of the velocity vector. ##\vec{N}(t) =...
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