Difference between revisions of "NSolve Command"
From GeoGebra Manual
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(change < to < and added * NSolve will work only if the function is continuous) |
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:*<code><nowiki>NSolve[a^4 + 34a^3 = 34, a = 3]</nowiki></code> yields ''{a = 0.99}''.</div>}} | :*<code><nowiki>NSolve[a^4 + 34a^3 = 34, a = 3]</nowiki></code> yields ''{a = 0.99}''.</div>}} | ||
| − | ;NSolve[ | + | ;NSolve[ <List of Equations>, <List of Variables> ] |
:Attempts (numerically) to find a solution of the set of equations for the given set of unknown variables. | :Attempts (numerically) to find a solution of the set of equations for the given set of unknown variables. | ||
:{{example|1=<div><code><nowiki>NSolve[{pi / x = cos(x - 2y), 2 y - pi = sin(x)}, {x = 3, y = 1.5}]</nowiki></code> yields ''{x = 3.141592651686591, y = 1.570796327746508}''.</div>}} | :{{example|1=<div><code><nowiki>NSolve[{pi / x = cos(x - 2y), 2 y - pi = sin(x)}, {x = 3, y = 1.5}]</nowiki></code> yields ''{x = 3.141592651686591, y = 1.570796327746508}''.</div>}} | ||
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* The number of decimals depends on the choosen in [[Options Menu#Runding|global rounding]]. | * The number of decimals depends on the choosen in [[Options Menu#Runding|global rounding]]. | ||
* NSolve won't work for functions that are asymptotic to the x-axis. They can often be reformulated though | * NSolve won't work for functions that are asymptotic to the x-axis. They can often be reformulated though | ||
| + | * NSolve will work only if the function is continuous | ||
* See also [[Solve Command]] and [[NSolutions Command]]. | * See also [[Solve Command]] and [[NSolutions Command]]. | ||
</div>}} | </div>}} | ||
Revision as of 21:26, 21 August 2015
- NSolve[ <Equation> ]
- Attempts (numerically) to find a solution for the equation for the main variable. For non-polynomials you should always specify a starting value (see below).
- Example:
NSolve[x^6 - 2x + 1 = 0]yields {x = 0.51, x = 1}.
- NSolve[ <Equation>, <Variable> ]
- Attempts (numerically) to find a solution of the equation for the given unknown variable. For non-polynomials you should always specify a starting value (see below).
- Example:
NSolve[a^4 + 34a^3 = 34, a]yields {a = -34.00086498588374, a = 0.9904738885574178}.
- NSolve[ <Equation>, <Variable = starting value> ]
- Finds numerically the list of solutions to the given equation for the given unknown variable with its starting value.
- Examples:
NSolve[cos(x) = x, x = 0]yields {x = 0.74}NSolve[a^4 + 34a^3 = 34, a = 3]yields {a = 0.99}.
- NSolve[ <List of Equations>, <List of Variables> ]
- Attempts (numerically) to find a solution of the set of equations for the given set of unknown variables.
- Example:
NSolve[{pi / x = cos(x - 2y), 2 y - pi = sin(x)}, {x = 3, y = 1.5}]yields {x = 3.141592651686591, y = 1.570796327746508}.
Note:
- If you don't give a starting point like a=3 or {x = 3, y = 1.5} the numerical algorithm may find it hard to find a solution (and giving a starting point doesn't guarantee that a solution will be found)
- The number of decimals depends on the choosen in global rounding.
- NSolve won't work for functions that are asymptotic to the x-axis. They can often be reformulated though
- NSolve will work only if the function is continuous
- See also Solve Command and NSolutions Command.
