How Do You Solve 5sin(a+30)=3 for Values of a?

[thomas49th]

Homework Statement

find the values of a to 1 decimal place for the interval 0 <= a <= 360 for which

5sin (a+30) = 3

The Attempt at a Solution

I know this is really easy but I've forgotten the method :(somthing like

(a + 30) = arcsin(3/5)
a + 30 = 36.869...

but I am not sure where to go from there.

Thanks

 

[HallsofIvy]

Homework Statement

find the values of a to 1 decimal place for the interval 0 <= a <= 360 for which

5sin (a+30) = 3

The Attempt at a Solution

I know this is really easy but I've forgotten the method :(


somthing like

(a + 30) = arcsin(3/5)
a + 30 = 36.869...

but I am not sure where to go from there.

Thanks

How about subtracting 30 from both sides?

 

[HallsofIvy]

Homework Statement

find the values of a to 1 decimal place for the interval 0 <= a <= 360 for which

5sin (a+30) = 3

The Attempt at a Solution

I know this is really easy but I've forgotten the method :(


somthing like

(a + 30) = arcsin(3/5)
a + 30 = 36.869...

but I am not sure where to go from there.

Thanks

What do you get if you subtract 30 from both sides?

 

[thomas49th]

a = 6.8...
so

a = 6.8, 180 - 6.869..,
a = 6.8 and 173.1...
is that my final answer?

 

[Redbelly98]

Looks good, how about checking those numbers back in the original equation? Then you can be sure.

I.e., does 5sin(6.869+30) equal 3? And similarly for 173.131