2cosA Bsin2A smplified equals cot A csc A cos B 2cot A cos

2cos(A - B)/sin(2A) smplified equals: cot A + csc A cos B 2cot A cosB - 2sinB cotAcosB - sin B cotAcosB + 2sinB cos A cos B- sin B cot Bcos + sinB cosB cscA - SinB sec A cosB cscA + sinB secA None of these An additional POLAR representation (point) for (r, theta) = (8, 5pi/3) is: (-8, -pi/3) (-8, 11pi/3) (8, 2pi/3) (-8, 2pi/3) (-8, 2pi/3) (-8, 4pi/3) None of these

Solution

12) 2*cos ( A-B) / sin 2A

2 [ cos A* cos B+ sin A* sin B] / 2*sin A*cos A

(cos A* cos B+ sin A* sin B) / sin A*cos A

= (cos A* cos B/ sin A*cos A ) + ( sin A* sin B  / sin A*cos A)

= cos B* cosec A + sin B * sec A ( ans h)

[ 1/ sin A = cosec A, 1/cos A = sec A]