solve/float
expressions involving floating-point numbers
Calling Sequence
Parameters
Description
Examples
solve(eqns, vars)
eqns
-
equations (as for solve), but with floating-point values
vars
variables (as for solve)
The solve function with floating-point numbers works by converting the floating-point numbers to approximate rationals, calling solve with these converted arguments, and converting the results back to floating-point numbers using evalf.
This can be convenient for solving equations with a combination of floating-point numbers and parameters (since fsolve will not solve equations with unassigned parameters). In most cases, it is a better idea to convert the input into exact values manually since this will generally give more meaningful answers.
eq≔x2−3x+0.01:
solveeq,x
2.996662955,0.00333704529
This is equivalent to the following:
eqe≔converteq,rational,exact
eqe≔x2−3x+1100
sol≔solveeqe,x
sol≔32+2145,32−2145
evalfsol
2.996662955,0.003337045
The variable x is a parameter in the following example
solve3.7y+z=sinx,x2−y=z,y,z
y=−0.3703703704x2+0.3703703704sinx,z=1.370370370x2−0.3703703704sinx
fsolve3.7y+z=sinx,x2−y=z,y,z
Error, (in fsolve) x is in the equation, and is not solved for
See Also
evalf
fsolve
realroot
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