" 9.If "180^(*)

.Find: (a) 3%" of "180

The value of the determinant Delta=|{:(sin^(2)23^(@)" "sin^(2)67^(@)" "cos180^(@)),(-sin^(2)67^(@)" "-sin^(2)23^(@)" "-cos180^(@)),(cos180^(@)" "sin^(2)23^(@)" "sin^(2)67^(@)):}| is

If ABCD is a cyclic quadrilateral then co (180^(@) +A) + cos (180^(@) - B) +cos(180^(@)-C) - sin (90^(@) - D)=

Solve : tan x + sec x = 1 (-180^(@) le x le 180^(@))

The sum of the three angles of a triangle is 180^(@)

If A, B, C, D are the four angle taken in order of a cyclic quadrilateral, prove that (ii) cos (180^(@) - A) + cos (180^(@) + B) + cos (180^(@) + C) - sin (90^(@) + D) = 0