Respuesta :
cosec(2t)=1/sin(2t) ==> 1/(2×cos(t)×sin(t))
cos(2t)= 1-2sin²t
or 2cos²t-1
or cos²t - sin²t
after we knew this informations we have to write it in the question
1/2×sint×cost-1/1/2×sint×cost=cos2t
-2×sint×cost+1/2sint×cost/1/2sint×cost=cos2t
the 2sint×cost will gone
-2×sint×cost+1=cos2t
lets take cos2t =1-2sin²t
-2×sint×cost+1=1-2sin²t
-2sint×cost=-2sin²t
cost=sint
that means the t is equal to 45 because sin45 and cos45 equal to √2/2
hopefully i didn't waste your time by reading and not understanding my English is not that good sorry
Answer:
see explanation
Step-by-step explanation:
Using the identities
cosec x = [tex]\frac{1}{sinx}[/tex] , 1 - sin²θ = 1
Consider the left side
[tex]\frac{cosec^20-1}{cosec^20}[/tex]
= [tex]\frac{\frac{1}{sin^20}-\frac{sin^20}{sin^20} }{\frac{1}{sin^20} }[/tex]
= ( [tex]\frac{1}{sin^20}-\frac{sin^20}{sin^20}[/tex] ) × [tex]\frac{sin^20}{1}[/tex] ← distribute parenthesis by sin²θ
= 1 - sin²θ
= cos²θ
= right side, thus proven