cos square 24 degree – cos square 6 degree =

A)(root5-1)/2 B)(root5+1)/2 C)(root5-1)/8 D)-(root5-1)/8

Dear Student

cos²24 = 1 –sin²24......(1)
cos²6 = 1 –sin²6........(2)
subtracting equation 2 from 1
letcos square 24 degree – cos square 6 degree =x
x= – sin²24 + sin²6



so answer will be (1/8) ( 1 – √5)

Thanks