In degrees: 3π/4 radians = 135°
Angle of x=135° is in the 2nd Quadrant and has negative cos x values and positive sin x values.
cos 135° = cos ( 90° + 45°)= - sin 45° =

sin 135° = sin ( 90° + 45° ) = cos 45° =

. You can also see the graph in the attachment.
You want to isolate x. To accomplish this, add 1.4 to both sides of your eqn.:
x = 7.82 + 1.4 = 9.22 (answer)
Answer:
3
Step-by-step explanation: