Question

How to find amplitude and period from equation?

Answer 1

If your graph is a COS or SIN graph :

$y = a \sin(bx) + c$
a is the Amplitude
and period is:
$\frac{360}{b}$

If your graph is a TAN graph :
$y = a \tan(bx) + c$
A TAN graph has no amplitude as it has no Maximum or Minimum value.
To find period :
$\frac{180}{b}$