Since cos(x-\pi/2)=sin(x), we can simplify the expression into
4sin(x)+1
If you know the graph of sin(x), then you have simply multiplied the function by 4, and then added 1.
Multiplying by four results in a vertical stretch. In fact, where sin(x) is zero, 4sin(x) is still zero. On the other hand, the maxima and minima (which of course are 1 and -1), now become 4 and -4. All the intermediate points must follow accordingly, and so, the function result stretched.
When you add 1, you are not associating anymore y=f(x), but y=f(x)+1. This means that you have added one unit to the y coordinate, which means that you translated the graph one unit upwards. Here are the graph of the changes:
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The fact that cos(x-pi/2)=sin(x), here
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The vertical stretch from sin(x) to 4sin(x), here
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The upward shift from 4sin(x) to 4sin(x)+1, here
