Recent content by Chadlee88

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    Linear algebra normalising a vector?

    Homework Statement Let the vector V = (x1,y1,z1) x1' = x1/sqrt(x1^2 + y1^2 + z1^2) y1' = x1/sqrt(x1^2 + y1^2 + z1^2) z1' = x1/sqrt(x1^2 + y1^2 + z1^2) What do you call x1', y1' and z1' in mathematics terms? is x1' the norm of x1 and y1' the norm of y1? Thanx Homework...
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    Moving Ball on sloping surface issue

    Ok...thanx for that...but i have no idea what all those formulas you jst posted mean. like F support, r normal, F, Mr equivalent etc. Could you please explain what all that is about cos yeh...i don't get any of it. Like i said, i haven't done physics for 4 years. If i don't get the forumulas...
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    Moving Ball on sloping surface issue

    Homework Statement Hey, I'm currently working a software project where I have a ball on a flat square plane and that plane can tilt up and down and left and right and at a combined angle in both direction for example diagonally. I haven't done physics since high school (4yrs ago) and I've...
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    Coding Theory, Finding Dual Code

    Homework Statement Let S = {0101, 1010, 1100}. From first principles, find a basis B for the dual code C orthogonal (couldn't find symbol) Homework Equations http://www.maths.uq.edu.au/courses/MATH3302/files/codingnotes.pdf i'm using page 19,20 and 21 The Attempt at a Solution...
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    Flux Problem: Calculate from (4,6) to (2,6)

    Homework Statement Calculate the flux: line from (4,6) to (2,6) using formula: integral v.n dS where v = -yi+xj n = j Parametrising: x = t: y = 6 Therefore r(t) = ti+6j r'(t) = i dS = |r't|dt =>dS = dt v.n = (-6i+tj) . (j) => t (As line is going from right to left (4,6) to...
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    Find the eigenvalues of a matrix

    Homework Statement i'm trying to find the eigenvalues of a matrix and i have the solution but i don't understand how it gets from the step 1 to step 2? could someone please explain. let # = lambda Step 1: (1-#)[(2-#)(-1-#)+1]+[3(-1-#)+2]+4[3-2(2-#)] = 0 Step 2: (1-#)(#+2)(#-3) = 0...
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    Integral with cosine and exponential - cos (2t) x e^2t

    yeh i did that, but i was still stuck, i made u= 2t so i had to find the integral of 1/2(cos (u)xe^u.
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    Integral with cosine and exponential - cos (2t) x e^2t

    Homework Statement can som1 please give me an idea where to start with this integral. integral of: cos (2t) x e^2t thanx Homework Equations The Attempt at a Solution
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    LU Matix decomposition problem with U.

    Homework Statement i'm trying to put the 3x3 matrix: [4 2 6] [ 2 8 2] [-1 3 1] into row echelow from. but i don't know where I'm goin wrong in my row operations. could some1 please tell...
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    Row Echelon Form Homework - Finding Mistake

    ? I'm trying to find the LU decomposition so U is jst an upper triangular matrix and that's what my answer above is. and from the fact that det(A) = det(LU) = det(L)det(U) = det(U) as det(L) = 1 the determinant of A has to be equal to the determinant of U. i worked out the determinant of A to...
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    Row Echelon Form Homework - Finding Mistake

    Homework Statement i'm trying to put the 3x3 matrix: [4 2 6] [ 2 8 2] [-1 3 1] into row echelow from. but i don't know where I'm goin wrong in my row operations. could some1 please tell me where i hav...
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    What are the critical points of a function with multiple variables?

    Partial derivatives (6x^2+y^2+10x)i + (2xy+2y)j how am i supposed to find values of x and y that make it equal to zero?? the partial derivative with respect to x is a quadratic function with both x and y terms. so I'm stuck!
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    What are the critical points of a function with multiple variables?

    Homework Statement Find all the critical points of f(x,y) = 2x^3+xy^2+5x^2+y^2+100 Homework Equations The Attempt at a Solution I'm really not sure how to do this question due the the x^3 term in the function. Could someone please advise how to start this. Thanx :D
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    Direction of Greatest Rate of Change for Function f(x, y, z) in the Plane z = 1

    So i'll get grad f = (2xz^4)i-(2yz^4)j - (4z^3 x^2 - 4z^3 y ^2)k And i substitute, x = 1, y=-2 and z=3 into grad f: and i get, the coordinates, (162, 324,972). <----Is this right? does that fact that it is on the plane z= 1 hav anything to do with the solution? Thanx
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    Direction of Greatest Rate of Change for Function f(x, y, z) in the Plane z = 1

    Homework Statement For the function f(x, y, z) = z^4(x^2 − y^2), find the coordinates of those points in the plane z = 1 at which the direction of the greatest rate of change of f is parallel to the vector i − 2j + 3k. Homework Equations The Attempt at a Solution i just want...
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