I am trying to add a WordPress featured image in a tag. I used these 3 shortcodes.

<?php echo $image_large[0]; ?>
<?php echo get_the_post_thumbnail(null,'thumbnail');?>
<?php echo get_the_post_thumbnail( $page->ID, 'full' ); ?>

Example

<a href="<?php echo get_the_post_thumbnail( $page->ID, 'full' ); ?>" >View Larger</a>

But nothing working. Please help me …