Question

1. Make a table and draw the graph of y= sin x–cos x for x in the range 0°≤x≤360°, with y values to 2dp and x intervals of 30° 
2. use the graph to find the value of y when
   1. x=75° 
   2. x=255° 
3. find the values of x for which y= – 0.9

Answer 1

1. x	0	30	60	90	120	150	180	210	240	270	300	330	360
   Sin x	0	0.5	0.87	1	0.87	0.5	0	−0.5	−0.87	−1	−0.87	−0.5	0
   Cos x	1	0.87	0.5	0	−0.5	−0.87	−1	−0.87	−0.5	0	0.5	0.87	1
   y	−1	−0.37	0.37	1	1.37	1.37	1	0.37	−0.37	−1	−1.37	−1.37	−1

   
   
2.  
   1. 0.75 ± 0.05      
   2. 0.675 ± 0.05    
3. 6°, 264°    ±6°