suppose-that-we-don-t-have-a-formula-for-g-x-but-we-know-that-g-1-3-and-g-x-x-2
Linearization of f(x) at a
##L(x)=f(a)+f'(a)(x-a)##
Let us find the linearization ##L(x)## of ##g(x)## at ##1##.
Since ##g(1)=-3## and ##g'(1)=sqrt{(1)^2+8}=3##,
##L(x)=g(1)+g'(1)(x-1)=-3+3(x-1)=3x-6##.
So, we can approximate:
##g(0.9) approx L(0.9)=3(0.9)-6=-3.3##
##g(1.1) approx L(1.1)=3(1.1)-6=-2.7##
I hope that this was helpful.
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