What formula would be used to calculate the right rectangle approximation of " (sin x . cosa ) da using four subintervals? O RA = () { [sin ( ) cos ( z)] + [sin() cos(7)] + [sin ( 2 ) cos (2 ) ] + [sin(2 ) cos(27)]} O RA = (#) { [sin(0) cos(0)] + [sin ( ) cos (7)] + [sin() cos(7)] + [sin ($," ) cos (3, ) ]} O R4 = [sin(0) cos(0)] + sin () cos ( ) ] + [sin(7) cos(7)] + sin (" ) cos (2 O RA = (") { [sin (#) cos (#)] + [sin (37 ) cos (37 )] + [sin ( 57 ) cos ( 5x) ] + [sin " cos 'n]}