Question

In any quadrilateral ABCD find the value of Cos ( A + B ) - Cos ( C + D ) 9. If ( n + 1 ) ! = 12 x ( n - 1 ) ! , find n

Answer 1

Answer:

In quadrilateral ABCD, A + B + C + D = 360

C+ D = 360 - (A + B)

Step-by-step explanation:

Cos (A + B) - Cos(C + D)

= Cos (A + B) - Cos[360 - (A + B)]

= Cos (A + B) - Cos (A + B)

= 0

(n + 1)! = 12 × (n - 1)!

(n + 1)n(n - 1)! = 12 × (n - 1)!

(n + 1)n = 12

(n + 1)n = 4 × 3

on comparing

n = 3

Answer 2

Answer:

this is correct............................