Question

if ABCD is a quadrilateral, then sec²(A+B/4)-cot²(C+D/4)=?​

Answer 1

Answer:

Untagged

If ABCD is a quadrilateral then tan(4A+B)=

A

cos(4C−D)

B

−cot(4C−D)

C

cot(4C+D)

D

−cot(4C+D)

Answer

ABCD is a quadrilateral.

We know, sum of four angles of a quadrilateral is 360o.

⇒  A+B+C+D=360o

⇒  A+B+C+D=2(180o)

⇒  A+B+C+D=2π

⇒  A+B=2π−(C+D)

Dividing both sides by 4 we get,

⇒  4A+B=2π−4C+D

Multiplying both sides by tan we get,

⇒  tan(

Answer 2

Answer:

answer I want for this question