Difference between revisions of "NSolutions Command"
From GeoGebra Manual
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The following commands are only available in the [[File:Menu view cas.svg|link=|16px]] [[CAS View]]. | The following commands are only available in the [[File:Menu view cas.svg|link=|16px]] [[CAS View]]. | ||
− | ;NSolutions | + | ;NSolutions( <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) | :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|1=<br><code><nowiki>NSolutions[x^6 - 2x + 1 = 0]</nowiki></code> yields ''{0.51, 1}'' or ''{0.508660391642, 1}'' (the number of decimals depends on the choosen in [[Options Menu#Rounding|global rounding]])}} | :{{example|1=<br><code><nowiki>NSolutions[x^6 - 2x + 1 = 0]</nowiki></code> yields ''{0.51, 1}'' or ''{0.508660391642, 1}'' (the number of decimals depends on the choosen in [[Options Menu#Rounding|global rounding]])}} | ||
− | ;NSolutions | + | ;NSolutions( <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) | :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|1=<div><code><nowiki>NSolutions[a^4 + 34a^3 = 34, a]</nowiki></code> yields '' {a = -34.00086498588374, a = 0.9904738885574178}''.</div>}} | :{{example|1=<div><code><nowiki>NSolutions[a^4 + 34a^3 = 34, a]</nowiki></code> yields '' {a = -34.00086498588374, a = 0.9904738885574178}''.</div>}} | ||
− | ;NSolutions | + | ;NSolutions( <Equation>, <Variable = starting value> ) |
:Finds numerically the list of solutions to the given equation for the given unknown variable with its starting value. | :Finds numerically the list of solutions to the given equation for the given unknown variable with its starting value. | ||
:{{examples|1=<div> | :{{examples|1=<div> | ||
:*<code><nowiki>NSolutions[cos(x) = x, x = 0]</nowiki></code> yields ''{0.74}'' | :*<code><nowiki>NSolutions[cos(x) = x, x = 0]</nowiki></code> yields ''{0.74}'' | ||
:*<code><nowiki>NSolutions[a^4 + 34a^3 = 34, a = 3]</nowiki></code> yields the list ''{-34, 0.99}''.</div>}} | :*<code><nowiki>NSolutions[a^4 + 34a^3 = 34, a = 3]</nowiki></code> yields the list ''{-34, 0.99}''.</div>}} | ||
− | ;NSolutions | + | ;NSolutions( <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=<br><code><nowiki>NSolutions[{pi / x = cos(x - 2y), 2 y - pi = sin(x)}, {x = 3, y = 1.5}]</nowiki></code> yields the list ''{3.14, 1.57}''}} | :{{example|1=<br><code><nowiki>NSolutions[{pi / x = cos(x - 2y), 2 y - pi = sin(x)}, {x = 3, y = 1.5}]</nowiki></code> yields the list ''{3.14, 1.57}''}} |
Revision as of 17:15, 7 October 2017
The following commands are only available in the CAS View.
- NSolutions( <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:
NSolutions[x^6 - 2x + 1 = 0]
yields {0.51, 1} or {0.508660391642, 1} (the number of decimals depends on the choosen in global rounding)
- NSolutions( <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:
NSolutions[a^4 + 34a^3 = 34, a]
yields {a = -34.00086498588374, a = 0.9904738885574178}.
- NSolutions( <Equation>, <Variable = starting value> )
- Finds numerically the list of solutions to the given equation for the given unknown variable with its starting value.
- Examples:
NSolutions[cos(x) = x, x = 0]
yields {0.74}NSolutions[a^4 + 34a^3 = 34, a = 3]
yields the list {-34, 0.99}.
- NSolutions( <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:
NSolutions[{pi / x = cos(x - 2y), 2 y - pi = sin(x)}, {x = 3, y = 1.5}]
yields the list {3.14, 1.57}
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.
- NSolutions won't work for functions that are asymptotic to the x-axis. They can often be reformulated though.
- NSolutions will work only if the function is continuous
- See also Solutions Command and NSolve Command.