The identity csc x - cot x = sin x/(1+cos x) has to be
proved.
Start from the left hand
side
csc x - cot x
csc x = 1/
sin x and cot x = cos x/ sin x
=> 1/sin x - cos
x/sin x
=> (1 - cos x)/sin
x
=> (1 - cos x)(1 + cos x)/(sin x)*(1 + cos
)
=> (1 - (cos x)^2)/(sin x)*(1 + cos
)
=> (sin x)^2/(sin x)*(1 + cos
)
=> sin x / (1 + cos
)
which is the right hand
side.
This proves csc x - cot x = sin
x/(1+cos x)
No comments:
Post a Comment