Question

if cot(a +b)=0,then sin(a+2b) is equal to

a)sin a

b)cos 2b

c)cos a

d)sin 2a

Answer 1

hi friend ur answer is in the above pic.
and the correct option is a)sin a

Answer 2

Answer:

Sin(A+2B) = cosB

Step-by-step explanation:

Given cot(A+B)=0

=> cot(A+B) = cot90°

=> A+B = 90° --(1)

Now,

sin(A+2B)

= sin[(A+B)+B]

= sin(90°+B) /* From (1)*/

= cosB

Therefore,

Sin(A+2B) = cosB

•••♪