Find the amplitude of y = -4 sin x.

Question

raffle_snaffle · Answer

Is this precalc?

raffle_snaffle · Answer

The amplitude is -4

anonymous · Answer

wouldn't it just be 4?

raffle_snaffle · Answer

^^^Yes you are correct it's just 4.

anonymous · Answer

ahahahahahah, yay :)

terenzreignz · Answer

Okay, let's have a look at your generic sine wave (note that it makes no difference if it were sin instead of cos, the basic principles remain the same)

terenzreignz · Answer

$$\Large y = \color{blue}a \cos(\color{orange}px + \color{green}q)+ b$$

terenzreignz · Answer

The amplitude is given by 
$$\Large |\color{blue}a|$$

terenzreignz · Answer

The amplitude is the highest value your function could possibly take (without the shift)
And since cosine (or sine) can only ever be as high as 1, then, the entire function can only ever be as high as you coefficient of your trig-function.

terenzreignz · Answer

If you're ever asked what the PERIOD is, then consider that coefficient of the x (inside the cos or sin)


Divide $\large 2\pi$ by that coefficient and you'll have the period.
$$\Large T = \frac{2\pi }p$$