title: angular 2 checkbox checked=true is not working
body: <p><strong>home.ts</strong></p>
  
  <pre><code>&lt;div class="col-xs-12 col-sm-3  col-md-3 radios"&gt;
      &lt;input [(ngModel)]="SEARCH_TYPE" [checked]="true"  type="radio" name="SEARCH_TYPE" placeholder="Starts With" title="Starts With" tab-index="" value="S" /&gt;
  &lt;/div&gt;
  &lt;div class="col-xs-12 col-sm-3  col-md-3 radios"&gt;
      &lt;input  [checked]=true [(ngModel)]="SEARCH_TYPE" type="radio" name="SEARCH_TYPE" placeholder="Contains" title="Contains" tab-index="" value="C" /&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Here the second input checkbox field is by deafult checked stage,but cant see checked in radio button</p>