find the amplitude of y = -3 sin 4x

Question

find the amplitude of y = -3 sin 4x

Answer 1

The general form of a sine function is:

 

y = a·sin(b(x+c)) + d

• a = amplitude
• b = angular frequency = 2pi/period
• c = horizontal (phase) shift
• d = vertical shift

 

So, in y = -3·sin(4x)

• a = -3
• b = 4
• c = 0
• d = 0