# user3.1415

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bio website location age 19 member for 2 years, 9 months seen Apr 18 at 9:11 profile views 24

# 62 Actions

 Jul2 awarded Curious Apr11 awarded Popular Question Sep30 awarded Popular Question Dec17 awarded Yearling Jun23 awarded Autobiographer Jun17 accepted Linear transformation for projection of a point on a line Jun17 comment Linear transformation for projection of a point on a line So, I was close! Thank you very much for the last missing bits. It seems obvious now. Jun17 revised Linear transformation for projection of a point on a line added 4 characters in body Jun17 asked Linear transformation for projection of a point on a line Jun14 accepted Prove: if $A(x)$ is divisible by $(x-a)^m$, its derivative is divisible by $(x - a)^{m-1}$ Jun14 revised Prove: if $A(x)$ is divisible by $(x-a)^m$, its derivative is divisible by $(x - a)^{m-1}$ edited title Jun14 comment Prove: if $A(x)$ is divisible by $(x-a)^m$, its derivative is divisible by $(x - a)^{m-1}$ The first tip was what I needed. Do you write the answer or do I do? Jun14 asked Prove: if $A(x)$ is divisible by $(x-a)^m$, its derivative is divisible by $(x - a)^{m-1}$ Jun9 answered Plotting a quadratic equation in the $\,xy\,$- plane Apr26 awarded Critic Feb5 comment Trigonometric equality $\cos x + \cos 3x - 1 - \cos 2x = 0$ I've not succeeded in finding a general formula. I've written down all formula's for $\cos(2x)$ to $\cos(5x)$ but I can only find one similarity in them: \begin{align} \cos(n \cdot x) &= a_1 \cos^nx - a_2 \cos^{n-2}x + a_3 \cos^{n-4}x - … \end{align} But I can't find $a_1$, $a_2$, etc. Feb5 comment Trigonometric equality $\cos x + \cos 3x - 1 - \cos 2x = 0$ \begin{alignX} \end{alignX} (without the X's) will do the trick, no dollar signs needed Jan31 revised Trigonometric equality $\cos x + \cos 3x - 1 - \cos 2x = 0$ added 676 characters in body Jan31 comment Trigonometric equality $\cos x + \cos 3x - 1 - \cos 2x = 0$ I'm studying for a test for tomorrow, so I don't have the time to do it now. But this intrigues me and I'll definitely will try it tomorrow. I'll come back to your comments. Jan31 revised Trigonometric equality $\cos x + \cos 3x - 1 - \cos 2x = 0$ added 676 characters in body