Google Earth Engine equation for fractional vegetation using NDVI

I want to write an equation for fractional vegetation in Google Earth Engine using NDVI.

My code is;

var ndviClip = ndvi.clip(table);
Map.addLayer(ndviClip, {min: -1, max: 1, palette: ['FF0000', '00FF00']});
print(ndviClip);

var min = ndviClip.reduceRegion({
reducer: ee.Reducer.min(),
geometry: box,
scale: 30,
maxPixels: 1e9
});

var max = ndviClip.reduceRegion({
reducer: ee.Reducer.max(),
geometry: box,
scale: 30,
maxPixels: 1e9
});

var fv=ndviClip.subtract(min).(divide(max.subtract(min)));

//min and max are ndviClip image min max values

It gives an error for the final line. How I can write an equation in Google Earth Engine for this kind of situation

• Welcome to GIS SE! We're a little different from other sites; this isn't a discussion forum but a Q&A site. Please check out our short tour to learn about our focussed Q&A format. What is the precise wording of the error? – PolyGeo Dec 13 '18 at 22:58

Without being able to access your image, I guess this should work for your equation:

var min = ee.Number(ndviClip.reduceRegion({
reducer: ee.Reducer.min(),
geometry: box,
scale: 30,
maxPixels: 1e9
}).values().get(0));

print(min)

var max = ee.Number(ndviClip.reduceRegion({
reducer: ee.Reducer.max(),
geometry: box,
scale: 30,
maxPixels: 1e9
}).values().get(0));

print(max)

var fv = ndviClip.subtract(min).divide(max.subtract(min));
print(fv)