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Algebra Help - Concrete Neutral axis

Algebra Help - Concrete Neutral axis

Algebra Help - Concrete Neutral axis

(OP)
Probably a stupid question, but need some basic algebra help regarding elastic analysis of rectangular section.
Solve for k:

How do you get from
k^2/n(1-k) = 2p

to

k = (sqroot 2pn + (pn)^2)-pn

If someone could break that down that would be great.

RE: Algebra Help - Concrete Neutral axis

well greg did two steps together ...

multiply by n(1-k) to get k^2 = 2pn(1-k)

then subtract the right hand side to get k^2+2pnk-2pn = 0

solution of quadratic k = -b+-sqrt(b^2-4ac)/2a ... k = -2pn+-sqrt((2pn)^2-4(-2pn))/2
k = -pn+-sqrt(4((pn)^2+2pn))/2
k = -pn+sqrt((pn)^2+2pn) ... the "-" gets an unreal -ve solution
that's nearly what you've written, with some "tolerance" on where the brackets are ...

another day in paradise, or is paradise one day closer ?

RE: Algebra Help - Concrete Neutral axis

(OP)
Thankyou both. Rb1957 cheers for the extra steps :)

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