Step-by-step derivation
S001 · implies
Before
declared real formula on all R;derivative means the two-sided h->0 quotient limit
After
finite-step evaluation and derivative existence are separate
Conditions: none
A derivative is the two-sided limit of[f(x+h)−f(x)]/h as h→0 with h≠0.One finite evaluation is not evidence that an arbitrary function is differentiable.
Step identifiers and dependencies
Rule: derivative_limit_definition_scope · Uses: G001
S002 · calculation
Before
at original x a*x := mul(22, 0)
After
at original x a*x = 0
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S001
S003 · calculation
Before
at original x a*x+b := sum(0, 10)
After
at original x a*x+b = 10
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S002
S004 · calculation
Before
at original x (a*x+b)*x := mul(10, 0)
After
at original x (a*x+b)*x = 0
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S003
S005 · calculation
Before
at original x f(x) := sum(0, 44)
After
at original x f(x) = 44
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S004
S006 · implies
Before
f(t)=(22)*t^2+(10)*t+(44);x=0;f(x)=44;h!=0
After
f(x+h)-f(x)=h*(2*(22)*(0)+(10)+(22)*h)
Conditions: none
Expand(x+h)²=x²+2xh+h²,cancel the original terms,and factor out h.The a2=0 lower-degree case is valid;no nonzero-leading-coefficient assumption is added.
Step identifiers and dependencies
Rule: quadratic_increment_factorization · Uses: G001, S005
S007 · calculation
Before
twice quadratic coefficient := mul(2, 22)
After
twice quadratic coefficient = 44
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S006
S008 · calculation
Before
twice a times x := mul(44, 0)
After
twice a times x = 0
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S007
S009 · calculation
Before
linear part of quotient := sum(0, 10)
After
linear part of quotient = 10
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S008
S010 · calculation
Before
shifted input x+h := sum(0, 2)
After
shifted input x+h = 2
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S009
S011 · calculation
Before
at shifted x a*x := mul(22, 2)
After
at shifted x a*x = 44
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S010
S012 · calculation
Before
at shifted x a*x+b := sum(44, 10)
After
at shifted x a*x+b = 54
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S011
S013 · calculation
Before
at shifted x (a*x+b)*x := mul(54, 2)
After
at shifted x (a*x+b)*x = 108
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S012
S014 · calculation
Before
at shifted x f(x) := sum(108, 44)
After
at shifted x f(x) = 152
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S013
S015 · calculation
Before
finite increment f(x+h)-f(x) := sub(152, 44)
After
finite increment f(x+h)-f(x) = 108
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S014
S016 · calculation
Before
specified finite quotient := div(108, 2)
After
specified finite quotient = 54
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S015
S017 · calculation
Before
finite-step quadratic correction := mul(22, 2)
After
finite-step quadratic correction = 44
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S016
S018 · calculation
Before
expanded finite quotient := sum(10, 44)
After
expanded finite quotient = 54
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S017
S019 · calculation
Before
finite quotient minus derivative := sub(54, 10)
After
finite quotient minus derivative = 44
Conditions: none
Evaluate exactly with this step's source operands and operation order.Check a denominator is nonzero before division.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S018
S020 · implies
Before
h=2;finite quotient=54/1;derivative value=10
After
difference=44;a2*h=44
Conditions: none
Keep the specified nonzero h:the answer is a finite quotient and differs from the derivative by a2*h.Special cases such as an affine model can agree numerically,but this does not identify a general finite quotient with a derivative or prove differentiability.
Step identifiers and dependencies
Rule: finite_difference_not_derivative_limit · Uses: G001, S019