-h
so, you are asked to find it with first principles?
well, you are asked to work it according to the limit definition instead of the more simpler rules
apply the formula, and the algebra works itself out
can we split it? or do we have to work it as one?
sqrt(c+h) + 2(c+h) - [sqrt(c)+2c] ---------------------------- h the only issue you may have problems with is the sqrt, which can be dealt with by a conjugate
the fraction splits so splitting is just a part of the work
1/2sqrt(1) + 2 is not going to be 1/2 so i think you left or omitted something along the way
lets work it out again ...
sqrt(c+h) + 2(c+h) - [sqrt(c)+2c] ---------------------------- h sqrt(c+h) + 2c +2h - sqrt(c)-2c ---------------------------- h sqrt(c+h) - sqrt(c) +2h+2c -2c ---------------------------- h sqrt(c+h) - sqrt(c) 2h --------------- + ---- h h sqrt(c+h) - sqrt(c) --------------- + 2 h the conjugate will help on the left term
(sqrt(c+h) - sqrt(c)) (sqrt(c+h) + sqrt(c)) ---------------------------------- h (sqrt(c+h) + sqrt(c)) c+h-c ------------------- h (sqrt(c+h) + sqrt(c)) h ------------------- h (sqrt(c+h) + sqrt(c)) 1 ------------------- (sqrt(c+h) + sqrt(c)) when h=0 this is just 1/2sqrt(c)
so, by the definition: we have 1/2sqrt(1) + 2 at x=1
huh
oh ok
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