Question
How to sketch the graph of sine from 0 to 360 degrees
Original question: 25 (a) Sketch the graph of for .
Expert Verified Solution
Key concept: The sine graph is one of the easiest full-cycle sketches once you know the anchor points. You do not need a calculator here; the standard angles tell the whole story.
Step by step
To sketch for , mark the key values of sine at the standard angles:
| 0 | |
| 1 | |
| 0 | |
| -1 | |
| 0 |
Shape of the curve
- Start at
- Rise smoothly to a maximum at
- Cross the axis at
- Fall to a minimum at
- Return to
The curve should be smooth and wave-like, not piecewise straight. Label the axes clearly, and make sure the peak and trough are at the correct heights.
A neat sketch with these points joined by a smooth sinusoidal curve is the expected graph.
Pitfall alert
Do not plot the sine graph like a zigzag. Another common issue is mixing up sine and cosine: cosine starts at 1, while sine starts at 0. Also remember that the question uses degrees, not radians.
Try different conditions
If the graph were , it would shift left and match cosine. If the question asked for , the same x-values would stay the same, but the maximum and minimum would become 2 and -2.
Further reading
amplitude, period, unit circle
FAQ
What are the key points for \(y=\sin x\) from 0° to 360°?
The key points are \((0,0)\), \((90,1)\), \((180,0)\), \((270,-1)\), and \((360,0)\).
Should the sine graph be drawn with straight lines?
No. It should be a smooth wave-like curve passing through the standard sine values.