code:

angular.module('CalcApp')
  .controller('XYZController', function ($scope, $route, localStorageService) {
		$scope.equation = {};
		$scope.equation.name = 'XYZ formula';
		$scope.equation.formula = '(a * 1.5) + 8 ± 2';
		$scope.change = function () {
			$scope.equation.outputLow = (($scope.equation.a * 1.5) + 8) - 2;
			$scope.equation.outputHigh = (($scope.equation.a * 1.5) + 8) + 2;
		};
		$scope.isFavorite = localStorageService.get('xyz');
		$scope.addFavorite = function() {
			localStorageService.add('xyz', true);
			$route.reload();
		};
		$scope.removeFavorite = function() {
			localStorageService.remove('xyz');
			$route.reload();
		};
	});