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Forum: General Questions - High School/Secondary
Welcome to the General Questions - High School/Secondary forum!
For discussing questions from any discipline at high school/secondary school level.

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jump to page: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 >> of 52 (257 items)

Equivalence of equations by Philidor on 2009-10-27 16:54:52
I was wondering whether everyone agrees that 0 is not in the solution set of the equation

(1) x*(1/x)=1

and that, hence, (1) is not equivalent to

(2) 1=1
[ reply | up ]
modeling using differential eq. by crazziqt467 on 2009-10-05 02:24:18
how would one model a diffential equation for growth of a population where the birth rate is not constant (dP/dt=aP) but rather proportional to P^k for some small positive constant k. Would it just be dP/dt=aP^k?

thanks!
[ reply | up ]
differential equations problem by crazziqt467 on 2009-10-03 20:41:45
I haven't dealt with differential equations in a while so I completely forget how to do this problem.

Given dx/dt=y and dy/dt=x

Verify that f(t)=Ce^t+De^-t and g(t)=Ce^t - De^-t give a solution to the system of differential equations, where C and D are arbitrary constants.

Thanks!
[ reply | up ]
Pivot position of a matrix by zee on 2009-09-25 23:00:24
Hi,

I would appreciate any feedback. Given matrix A = [ 1 c 0

 2 4 1

 3 5 1 ] , which number c leads to a zero in the second pivot position ? I reduced to triangular form and I thought c would be 2 but wouldn't that make entry a(3 3) have division by zero? So I thought that there would be no c which would lead to a zero in the 2nd pivot position.

Thanks for any help.
[ reply | up ]
Cube inside a octahedron by mathmenot on 2009-09-20 18:04:23
hello,
in the central points of a cube with the edge lenght of "a" we're constructing segements at a right angle and the lenght "h". so we have a cube with spiky segments.
the six ends of the segments forming a octahedron.
so now the questions are: how long is "h" when the edge lenght of the octahedron is "2a" (2 times the cube edge lenght's)?? and is the cube inside the octahedron in this case??
really hard to think about those three-dimensioal structures in the head, tried to sketch them but i'm a very bad drawer...
[ reply | up ]

jump to page: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 >> of 52 (257 items)

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