Question

state the signs of the trigonometric functions : sin 159°

Answer 1

The angles between 90 and 180 lie in the 2nd quadrant.

hence sin 159 lies in the 2nd quadrant and its sign is +ve.

Answer 2

sin 159degree =0.358..

as sin159 is less than 180 hence it is +ve.

trignometry follos rules as per the graph

***(sin=s ; tan = t ; cos= c)

1st quadrant :: all are +ve ( s t c)
2nd quadrant:: s is +ve & t , c are -ve
3rd quadrant :: t is +ve & s, c are -ve
4th quadrant :: c is +ve & s,t are -ve



trick to remember :: All Silver Tea Cups
( all , sin , tan , cos)
( 1, 2, 3 , 4 )