If the sol'ns are -9 and 9, then we can use this to form our eq'n:
(x - 9)(x + 9) = 0
x^2 - 81 = 0
so...
x^2 + z - 103 = x^2 -81
z - 103 = -81
z = -81 + 103
z = 22
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<span>let y = sec^2 ( pi x )
y' = 2 sec ( pi x ) sec( pi x ) tan ( pi x ) pi
y' = 2pi sec^2 ( pi x ) tan ( pi x )
y''= 2pi sec^2 ( pi x ) * sec^2 ( pi x ) * pi + 2pi tan ( pi x ) * 2pi sec^2 ( pi x ) tan ( pi x )
y'' = 2 pi^2 sec^4 ( pi x ) + 4 pi^2 sec^2 ( pi x ) tan^2 ( pi x )</span>
notice that the denominator can be factored into (x-3)(x+3).
Now you can cross out (x - 3) from the numerator and denomiantor resulting in a simplified fraction of 
Plug the limit value (which is 3) into the simplified fraction.
Answer: 
