Question

If the sin(35º) = 0.57 and cos(35º) = 0.82, find the sin(55º).

A) 0.18
B) 0.43
C) 0.57
D) 0.82

Answer 1

Option D) 0.82

Explanation:

we know that

`sin(A-B)= sin(A)cos(B)-cos(A)sin(B)`

so

we have that

`90\°-35\°=55\°`

substitute

`sin(90\°-35\°)= sin(90\°)cos(35\°)-cos(90\°)sin(35\°)`

we have

`sin(90\°)=1\\cos(90\°)=0\\sin(35\°)=0.57\\cos(35\°)=0.82`

substitute

`sin(90\°-35\°)= (1)(0.82)-(0)(0.57)`

`sin(90\°-35\°)= 0.82`

`sin(55\°)= 0.82`