Can we take AD as a perpendicular bisector of BC

Find the quadratic polynomial whose zeros are 1/2 and - 1/2

Sin30.cos60-tan45.sec30.cosec60

In a triangle ABC if the bisector of angle A and the perpendicular bisector of BC intersect then prove that they will intersect on the circumcircle of triangle ABC 

Two dairy owners A and B sell flavoured milk filled to capacity in mugs of negligible thickness, which are cylindrical in shape with a raised hemispherical bottom. The mugs are 14 cm high and have diameter of 7 cm as shown in given figure. Both A and B sell flavoured milk at the rate of Rs. 80 per litre. The dairy owner A uses the formula πr2h to find the volume of milk in the mug and charges Rs. 43.12 for it. The dairy owner B is of the view that the price of actual quantity of milk should be charged.What according to him should be the price of one mug of milk? Which value is exhibited by the dairy owner B?

Find the equation of hyperbola whose foci s (6,4)and s' (-4,4) and e=2

11th sum

Find the equation of locus of all points such that the difference  of their  distances  from (4,0)and (-4,0) is always equal to 2