Asked by Dickson
if Sin=(2theta-30degrees)= Cos=(3thetas+40degrees) then what is the value of the theta
Answers
Answered by
Reiny
sin(2Ø+30°) = cos(3Ø + 40°)
we know that sin x = cos (90-x)
so sin(2Ø-30) = cos(90 - 2Ø + 30)
= cos(120 - 2Ø)
then cos(120-2Ø)=cos(3Ø+40)
3Ø+40 = 120-2Ø
5Ø = 80
Ø = 16°
or
cos(3Ø + 40) = sin(90 - 3Ø-40) = sin(50-3Ø)
then 2Ø-30 = 50-3Ø
5Ø = 80
Ø = 16 , same answer
we know that sin x = cos (90-x)
so sin(2Ø-30) = cos(90 - 2Ø + 30)
= cos(120 - 2Ø)
then cos(120-2Ø)=cos(3Ø+40)
3Ø+40 = 120-2Ø
5Ø = 80
Ø = 16°
or
cos(3Ø + 40) = sin(90 - 3Ø-40) = sin(50-3Ø)
then 2Ø-30 = 50-3Ø
5Ø = 80
Ø = 16 , same answer