Average Error: 29.9 → 0.2
Time: 5.6s
Precision: binary64
Cost: 13248
\[\sqrt{x + 1} - \sqrt{x} \]
\[\frac{1}{\sqrt{1 + x} + \sqrt{x}} \]
(FPCore (x) :precision binary64 (- (sqrt (+ x 1.0)) (sqrt x)))
(FPCore (x) :precision binary64 (/ 1.0 (+ (sqrt (+ 1.0 x)) (sqrt x))))
double code(double x) {
	return sqrt((x + 1.0)) - sqrt(x);
}
double code(double x) {
	return 1.0 / (sqrt((1.0 + x)) + sqrt(x));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = sqrt((x + 1.0d0)) - sqrt(x)
end function
real(8) function code(x)
    real(8), intent (in) :: x
    code = 1.0d0 / (sqrt((1.0d0 + x)) + sqrt(x))
end function
public static double code(double x) {
	return Math.sqrt((x + 1.0)) - Math.sqrt(x);
}
public static double code(double x) {
	return 1.0 / (Math.sqrt((1.0 + x)) + Math.sqrt(x));
}
def code(x):
	return math.sqrt((x + 1.0)) - math.sqrt(x)
def code(x):
	return 1.0 / (math.sqrt((1.0 + x)) + math.sqrt(x))
function code(x)
	return Float64(sqrt(Float64(x + 1.0)) - sqrt(x))
end
function code(x)
	return Float64(1.0 / Float64(sqrt(Float64(1.0 + x)) + sqrt(x)))
end
function tmp = code(x)
	tmp = sqrt((x + 1.0)) - sqrt(x);
end
function tmp = code(x)
	tmp = 1.0 / (sqrt((1.0 + x)) + sqrt(x));
end
code[x_] := N[(N[Sqrt[N[(x + 1.0), $MachinePrecision]], $MachinePrecision] - N[Sqrt[x], $MachinePrecision]), $MachinePrecision]
code[x_] := N[(1.0 / N[(N[Sqrt[N[(1.0 + x), $MachinePrecision]], $MachinePrecision] + N[Sqrt[x], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\sqrt{x + 1} - \sqrt{x}
\frac{1}{\sqrt{1 + x} + \sqrt{x}}

Error

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original29.9
Target0.2
Herbie0.2
\[\frac{1}{\sqrt{x + 1} + \sqrt{x}} \]

Derivation

  1. Initial program 29.9

    \[\sqrt{x + 1} - \sqrt{x} \]
  2. Applied egg-rr29.2

    \[\leadsto \color{blue}{\left(x + \left(1 - x\right)\right) \cdot \frac{1}{\sqrt{x + 1} + \sqrt{x}}} \]
  3. Simplified0.2

    \[\leadsto \color{blue}{\frac{1}{\sqrt{1 + x} + \sqrt{x}}} \]
    Proof
    (/.f64 1 (+.f64 (sqrt.f64 (+.f64 1 x)) (sqrt.f64 x))): 0 points increase in error, 0 points decrease in error
    (/.f64 (Rewrite<= metadata-eval (+.f64 1 0)) (+.f64 (sqrt.f64 (+.f64 1 x)) (sqrt.f64 x))): 0 points increase in error, 0 points decrease in error
    (/.f64 (+.f64 1 (Rewrite<= +-inverses_binary64 (-.f64 x x))) (+.f64 (sqrt.f64 (+.f64 1 x)) (sqrt.f64 x))): 0 points increase in error, 0 points decrease in error
    (/.f64 (Rewrite<= associate--l+_binary64 (-.f64 (+.f64 1 x) x)) (+.f64 (sqrt.f64 (+.f64 1 x)) (sqrt.f64 x))): 126 points increase in error, 1 points decrease in error
    (/.f64 (-.f64 (Rewrite<= +-commutative_binary64 (+.f64 x 1)) x) (+.f64 (sqrt.f64 (+.f64 1 x)) (sqrt.f64 x))): 0 points increase in error, 0 points decrease in error
    (/.f64 (-.f64 (+.f64 x 1) (Rewrite<= rem-square-sqrt_binary64 (*.f64 (sqrt.f64 x) (sqrt.f64 x)))) (+.f64 (sqrt.f64 (+.f64 1 x)) (sqrt.f64 x))): 38 points increase in error, 24 points decrease in error
    (/.f64 (-.f64 (+.f64 x 1) (Rewrite<= sqr-neg_binary64 (*.f64 (neg.f64 (sqrt.f64 x)) (neg.f64 (sqrt.f64 x))))) (+.f64 (sqrt.f64 (+.f64 1 x)) (sqrt.f64 x))): 0 points increase in error, 0 points decrease in error
    (/.f64 (-.f64 (+.f64 x 1) (*.f64 (neg.f64 (sqrt.f64 x)) (neg.f64 (sqrt.f64 x)))) (+.f64 (sqrt.f64 (Rewrite<= +-commutative_binary64 (+.f64 x 1))) (sqrt.f64 x))): 0 points increase in error, 0 points decrease in error
    (/.f64 (-.f64 (+.f64 x 1) (*.f64 (neg.f64 (sqrt.f64 x)) (neg.f64 (sqrt.f64 x)))) (+.f64 (sqrt.f64 (+.f64 x 1)) (Rewrite<= remove-double-neg_binary64 (neg.f64 (neg.f64 (sqrt.f64 x)))))): 0 points increase in error, 0 points decrease in error
    (/.f64 (-.f64 (+.f64 x 1) (*.f64 (neg.f64 (sqrt.f64 x)) (neg.f64 (sqrt.f64 x)))) (Rewrite<= sub-neg_binary64 (-.f64 (sqrt.f64 (+.f64 x 1)) (neg.f64 (sqrt.f64 x))))): 0 points increase in error, 0 points decrease in error
    (Rewrite=> div-sub_binary64 (-.f64 (/.f64 (+.f64 x 1) (-.f64 (sqrt.f64 (+.f64 x 1)) (neg.f64 (sqrt.f64 x)))) (/.f64 (*.f64 (neg.f64 (sqrt.f64 x)) (neg.f64 (sqrt.f64 x))) (-.f64 (sqrt.f64 (+.f64 x 1)) (neg.f64 (sqrt.f64 x)))))): 42 points increase in error, 26 points decrease in error
    (-.f64 (/.f64 (+.f64 x 1) (-.f64 (sqrt.f64 (+.f64 x 1)) (neg.f64 (sqrt.f64 x)))) (/.f64 (Rewrite=> sqr-neg_binary64 (*.f64 (sqrt.f64 x) (sqrt.f64 x))) (-.f64 (sqrt.f64 (+.f64 x 1)) (neg.f64 (sqrt.f64 x))))): 0 points increase in error, 0 points decrease in error
    (-.f64 (/.f64 (+.f64 x 1) (-.f64 (sqrt.f64 (+.f64 x 1)) (neg.f64 (sqrt.f64 x)))) (/.f64 (Rewrite=> rem-square-sqrt_binary64 x) (-.f64 (sqrt.f64 (+.f64 x 1)) (neg.f64 (sqrt.f64 x))))): 23 points increase in error, 34 points decrease in error
    (Rewrite<= div-sub_binary64 (/.f64 (-.f64 (+.f64 x 1) x) (-.f64 (sqrt.f64 (+.f64 x 1)) (neg.f64 (sqrt.f64 x))))): 3 points increase in error, 6 points decrease in error
    (/.f64 (-.f64 (+.f64 x 1) x) (Rewrite=> sub-neg_binary64 (+.f64 (sqrt.f64 (+.f64 x 1)) (neg.f64 (neg.f64 (sqrt.f64 x)))))): 0 points increase in error, 0 points decrease in error
    (/.f64 (-.f64 (+.f64 x 1) x) (+.f64 (sqrt.f64 (+.f64 x 1)) (Rewrite=> remove-double-neg_binary64 (sqrt.f64 x)))): 0 points increase in error, 0 points decrease in error
    (/.f64 (Rewrite<= associate-+r-_binary64 (+.f64 x (-.f64 1 x))) (+.f64 (sqrt.f64 (+.f64 x 1)) (sqrt.f64 x))): 1 points increase in error, 1 points decrease in error
    (/.f64 (Rewrite<= *-rgt-identity_binary64 (*.f64 (+.f64 x (-.f64 1 x)) 1)) (+.f64 (sqrt.f64 (+.f64 x 1)) (sqrt.f64 x))): 0 points increase in error, 0 points decrease in error
    (Rewrite<= associate-*r/_binary64 (*.f64 (+.f64 x (-.f64 1 x)) (/.f64 1 (+.f64 (sqrt.f64 (+.f64 x 1)) (sqrt.f64 x))))): 0 points increase in error, 0 points decrease in error
  4. Final simplification0.2

    \[\leadsto \frac{1}{\sqrt{1 + x} + \sqrt{x}} \]

Alternatives

Alternative 1
Error0.3
Cost26308
\[\begin{array}{l} t_0 := \sqrt{1 + x} - \sqrt{x}\\ \mathbf{if}\;t_0 \leq 4 \cdot 10^{-5}:\\ \;\;\;\;0.5 \cdot {x}^{-0.5}\\ \mathbf{else}:\\ \;\;\;\;t_0\\ \end{array} \]
Alternative 2
Error0.8
Cost6980
\[\begin{array}{l} \mathbf{if}\;x \leq 1:\\ \;\;\;\;1 + \left(x \cdot 0.5 - \sqrt{x}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot {x}^{-0.5}\\ \end{array} \]
Alternative 3
Error1.9
Cost6788
\[\begin{array}{l} \mathbf{if}\;x \leq 0.25:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot {x}^{-0.5}\\ \end{array} \]
Alternative 4
Error31.1
Cost64
\[1 \]

Error

Reproduce

herbie shell --seed 2022329 
(FPCore (x)
  :name "Main:bigenough3 from C"
  :precision binary64

  :herbie-target
  (/ 1.0 (+ (sqrt (+ x 1.0)) (sqrt x)))

  (- (sqrt (+ x 1.0)) (sqrt x)))