Question

( frac{1}{cos 290}+frac{1}{sqrt{3} sin 250} )
( frac{1}{cos (270+20)}+frac{1}{sqrt{3} sin left(270-20^{circ}right)} )
( frac{1}{sin 20^{circ}}+frac{1}{sqrt{3}left(-cos 20^{circ}right)} )
( frac{1}{sin 20}-frac{1}{sqrt{3} cos 20} )
( operatorname{cosec} 20^{circ}-sqrt{3} sec 20^{circ} )
( frac{1}{2} times 2left(operatorname{cosec} 20^{circ}-sqrt{3} 9 operatorname{ec} 20right) )
( 2left[frac{1}{2} operatorname{cosec} 20^{circ}-frac{sqrt{3}}{2} sec 20right] )
( 2left[frac{sin 30}{sin 20}-frac{cos 30^{circ}}{cos 20}right] )
( 2left[frac{sin 30^{circ} cos 20^{circ}-cos 30^{circ} sin 20}{sin 20 cdot cos 20}right] )
( 2left[frac{sin (30-20)}{1 / 22 sin 20^{circ} cos 20}right]=4 frac{sin 10^{circ}}{sin 40^{circ}} )

# is equal to 28. cos 290.3 sin 250

Solution