NSolve Command

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).

NSolve(x^6 - 2x + 1 = 0) yields {x = 0.51, x = 1}.

CAS Syntax

These syntaxes are only available in the CAS View.

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).

NSolve(a^4 + 34a^3 = 34, a) yields {a = -34, a = 0.99}.

NSolve( <Equation>, <Variable = starting value> ): Finds numerically the list of solutions to the given equation for the given unknown variable with its starting value.

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.

NSolve({pi / x = cos(x - 2y), 2 y - pi = sin(x)}, {x = 3, y = 1.5}) yields {x = 3.14, y = 1.57}.

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 or other extreme examples. They can often be reformulated though.
NSolve will work only if the function is continuous!
See also Solve Command and NSolutions Command.