# How do I set a fixed scale on y-axis? [closed]

I wrote a simple example to show the pattern of a stationary wave, using codes as following:

Manipulate[Plot[a Sin[x], {x, 0, 2 Pi}], {a, 0, 1}]


However, when I'm running it, the scale of $y$-axis is changing as parameter a is changing. What I want is a fixed $y$-axis range from -1 to 1. What can I do?

P.S. I've tried 'AspectRatio', and it didn't really worked...

## closed as off-topic by MarcoB, Feyre, corey979, m_goldberg, yohbsJan 18 '17 at 2:58

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question arises due to a simple mistake such as a trivial syntax error, incorrect capitalization, spelling mistake, or other typographical error and is unlikely to help any future visitors, or else it is easily found in the documentation." – MarcoB, Feyre, corey979, m_goldberg, yohbs
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• Try PlotRange. – Kuba Jan 17 '17 at 13:13

As Kuba said in comments, the PlotRange option does what you want:
Manipulate[