angularjs - How to use $(this) in $scope functions on Angular JS + jQuery -

i wanted ask why $(this) selector doesn't work inside $scope functions in angular js + jquery.

i have sample code:

[javascript]

$scope.starttimer = function() {      $(this).hide(); } 

[html]

<button ng-click="starttimer()"> 

i've tried doing still doesn't work:

[javascript]

$scope.starttimer = function(btn) {      $(btn).hide(); } 

[html]

<button ng-click="starttimer(this)"> 

anyone knows how fix this? sorry noob question.

do angular way...

[html]

<button ng-click="starttimer()" ng-hide="btnhide"> 

[javascript]

$scope.starttimer = function(btn) {      btnhide = true; }