hp 39gs how to solve a quadratic equation

[yong han]

how to solve quadratic equation? solve this problem x^2+5=0. answer x=+-5i
i use solve aplet and quad explorer but it's not answer
how to solve this equation?

[ijabbott]

(04-30-2018 06:38 AM)yong han Wrote:  how to solve quadratic equation? solve this problem x^2+5=0. answer x=+-5i
i use solve aplet and quad explorer but it's not answer
how to solve this equation?

You can use POLYROOT([1,0,5]). The list inside the square brackets is the coefficients of the polynomial whose roots you wish to find. The result is a 1 by n matrix (for an nth degree polynomial) containing the roots. Note that a complex number is represented as an ordered pair of numbers in parentheses - (real,imag). For example 3+2i is represented as (3,2).

For example, POLYROOT([1,0,5]) => [(0,2.2360679775),(0,-2.2360679775)].