degress2meters.js

var degrees2meters = function(lon,lat) {
        var x = lon * 20037508.34 / 180;
        var y = Math.log(Math.tan((90 + lat) * Math.PI / 360)) / (Math.PI / 180);
        y = y * 20037508.34 / 180;
        return [x, y]
}

lon= -77.035974
lat = 38.898717

console.log(degrees2meters(lon,lat))

// should result in: -8575605.398444, 4707174.018280

meters2degress.js

var meters2degress = function(x,y) {
        var lon = x *  180 / 20037508.34 ;
        var lat =Number(180 / Math.PI * (2 * Math.atan(Math.exp(y * Math.PI / 180)) - Math.PI / 2));

        return [lon, lat]
}

x= -8575605.398444
y = 4707174.018280

console.log(meters2degress(x,y))

//should result in -77.035974 38.898717 but gives result -88.42920367320511 lat value. How to inverse that deym function?
//according to stack overflow lat value is => ll.Latitude = 180 / Math.PI * (2 * Math.Atan(Math.Exp(ll.Latitude * Math.PI / 180)) - Math.PI / 2);
//however how to deal with infinity at Math.Exp(ll.Latitude * Math.PI / 180)?
//toFixed will cause precision lose :( there can be recursive method which divide double variable for an array object