Recent content by invisible_man

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    Graduate What are the methods for solving y''' + y' = tan(t) 0<t<pi?

    y''' + y' = tan(t) 0<t<pi I got yh = c1 + c2cos(t) + c3sin(t) I'm trying to solve by Undetermined Coefficient method and Variation of Parameters method, but it didn't work
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    Prove n^3 <= 2^n: Homework via Induction

    how can i connect (n+1) n+1 to 2 n+1. Can you show me how
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    Prove n^3 <= 2^n: Homework via Induction

    Homework Statement Prove: n3 <= nn, n >= 10 Homework Equations The Attempt at a Solution Prove by induction on n. i) 1 = 1 1 < 2 ii) n +1 claim (n+1)3 <= 2n+1 , n >=10 I don't know how to induct with n+1, when n >=10
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    Graduate Find solution with initial value

    The Laplace Transform of ty' = -L[y]'
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    Graduate Find solution with initial value

    y'' - ty' + y = 1, y(0) = 1, y'(0) =2 I'm trying to solve by Laplace Transform and I got stuck at the end.Anyone can help me to solve it?
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    Graduate Finite Subset Max in Set S: Proof

    This is not really my homework assignment. It's my practice exam. I don't know how to do it
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    Graduate What is the Laplace Transform of (t-3)u2(t) - (t-2)u3(t)?

    Compute L[(t-3)u2(t) - (t-2)u3(t)] I come up with using unit step function but I don't know how to solve it
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    Graduate Proving Properties of an Ordered Ring: R+ & R

    Let R be an ordered Ring. Assume R+ is well-ordered Prove: a) min(R+) = 1. b) R is an integer ring
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    Graduate Finite Subset Max in Set S: Proof

    Let S be a set on which a linear order <= (less or equal) , is defined. Show that a non-empty finite subset has a max.
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    How Do You Calculate the Volume of a Solid Bounded by z=8xy in the First Octant?

    change to the sphendrical coordinate
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    Antiderivative homework question

    what is your question? take that integral or what? type it out your problem and question so I can understand it
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    Integration by parts (LIPET Or LIATE)

    i don't get it
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    Antiderivative homework question

    Oh dear, x = sqrt(x) * sqrt (x)
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    Antiderivative homework question

    you have the integral of x / sqrt(x) = integral of sqrt(x). integral of sqrt(x) = 2/3 * x^3/2
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    Antiderivative homework question

    you got wrong in "my working" . x is variable. so you can't take it out of the integral. 2sqrt(h) is constant so you can take to the front. 1/2sqrt(h) * integral sqrt(x) dx from 0 to h. = 1/2sqrt(h) * 2/3 * x^3/2 and evaluate at x = h. = 1/2sqrt(h) * 2/3 * h sqrt(h) = h/3