Question

express each of the following in terms of trigonometric ratios of angles between 0°and 45°. sin72° + cosec72°​

Answer 1

Step-by-step explanation:

sin72° + cosec72°

$\sin( {72}^{o} ) + \cosec( {72}^{o} ) \\ = \sin( {90}^{o} - {18}^{o} ) + cosec( {90}^{o} - {18}^{o} ) \\ = cos( {18}^{o} ) + \sec( {18}^{o} )$