- #1
raining Pete
- 371
- 0
Hello all, was wondering if you fine chaps / ladies could help with a bit of algebra. Annoyed it's had to come to this but alas my algebra levels keep leading me astray.
## x + y = c ##
## x^2 + h^2 = a^2 ##
## y^2 + h^2 = b^2 ##
I've been reading Measurements - Paul Lockhart (wish i picked this up 10 years ago) and the swine asks to first find x and y 'see if you can rearrange the equations to get':
## x = c/2 + (a^2 - b^2)/2c ##
## y = c/2 - (a^2 - b^2)/2c ##
After this it is to find h but i would like know the algebra behind finding x and y. I've swapped, rearranged and been all over the place, never the above though. For example,
## x^2 - y^2 = a^2 - b^2 ## ==>
## -x(x-1) + y^2 + y = c - a^2 - b^2 ## ==> etc,
trying quadratics, generally leading to nowhere or something else entirely.
Thanks for any help if given.
## x + y = c ##
## x^2 + h^2 = a^2 ##
## y^2 + h^2 = b^2 ##
I've been reading Measurements - Paul Lockhart (wish i picked this up 10 years ago) and the swine asks to first find x and y 'see if you can rearrange the equations to get':
## x = c/2 + (a^2 - b^2)/2c ##
## y = c/2 - (a^2 - b^2)/2c ##
After this it is to find h but i would like know the algebra behind finding x and y. I've swapped, rearranged and been all over the place, never the above though. For example,
## x^2 - y^2 = a^2 - b^2 ## ==>
## -x(x-1) + y^2 + y = c - a^2 - b^2 ## ==> etc,
trying quadratics, generally leading to nowhere or something else entirely.
Thanks for any help if given.
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