Trigonometry Maths Problem (1 Viewer)

[hit patel]

Hi guys i was doing ext 1 maths but these quadrant questions popped up and i cant get them. Questions like ' find exact values of sin 240' or 'when 0<theta<360, find the values of theta which satisfy tan theta=-3'. I just cant get them as there are 2 possible ways. The answer for tan theta=-3 can be 270- (inverse tan(3)) or 180+(inverse tan (3)) or 180 - (inverse tan 3) or 90 + (inverse tan 3). As you can see tan is negative in all these quadrants then why cant the answer be all four. all help is appreciated . If yyou can please answer in detail.

Thanks

 

[J-Wang]

240 degrees is in the third quadrant, so using ASTC, you can deduce that sin 240= -sin60, =-Root3/2