WAEC - Further Mathematics (2010 - No. 9)
If \(\sin x = -\sin 70°, 0° < x < 360°\), determine the two possible values of x.
110°, 250°
110°, 290°
200°, 250°
250°, 290°
Forklaring
The value of the sine of an angle is negative in the third and fourth quadrant. Hence options A and B are not the options.
\(\sin 250 = -\sin (250 - 180) = - \sin 70\)
\(\sin 290 = - \sin (360 - 290) = - \sin 70\)