Question

The amplitude of y=-3sinx is A. -3 B. -1 C. 3 D. 1/3​

Answer 1

Explanation:

Use the form a sin
`(bx - c) + d`to find the variables used to find the amplitude, period, phase shift, and vertical shift.

a=3

b=1

c=0

d=0

Find the amplitude |a|.

Amplitude: 3

So your answer is C. 3

Answer 2

C. 3.

Explanation:

We are given that

`y=-3sinx`

We have to find the amplitude of y =-3sinx

Amplitude:The absolute value of maximum displacement from a zero value during one period of oscillation.

Or

Amplitude: It can be maximum displacement from the mean position of any crest of trough .

If we have a function
`y= asint`

Then the amplitude is" a".

We have a function

`y=-3sinx`

Then amplitude is "3"

By comparing with the given function

Where negative sign represents the displacement in opposite direction.We can say that the displacement from mean position of trough is 3.Amplitude is define as the peak value of crest or trough.

Amplitude is a value of displacement therefor, it always a positive value not negative.

Hence, the option is C is true.