Question

Find the domain, period, range, and amplitude of the cosine function.

y = -6cos4x

Answer 1

Hint range = Find the largest number to the lowest number Then subtract.

Answer 2

I already know what the range is... thank you.

Answer 3

Period is equal to: 2pi/angular frequency

Answer 4

How do I find the angular frequency?

Answer 5

very often is the number that accompanies the x, but that depends how is expressed

Answer 6

Can you show me please?

Answer 7

The general equation is: A cos nx;
A is the amplitud;
n is the angular frequency;
if n were 1/2, You have to plug in the equation Period = 2 pi/ 1/2 ;
if n were 8 . you hato to plug ... period = 2pi/8;
In general, period = 2pi /n, since n is the angular frequency,
and again n is the number that accompanies the x

Answer 8

for example, if the equation is y = 10 sin x, WHat would be the period and the amplitude ?

Answer 9

Amplitude = 10

Period = 2 pi/ idk what the angular frequency is though o.o

Answer 10

is so easy
try to think what number multiplied by x is equal to x

Answer 11

2 pi/ 1

Answer 12

good !

Answer 13

So the period is 2 pi/ 4? o.o

Answer 14

or just 2pi is the same

Answer 15

of course
but you have first of all simplify

Answer 16

i mean the fraction

Answer 17

dividing both sides by two...?

Answer 18

sure! you almost got it totally

Answer 19

Just a little bit... I'm terrible at math /.\

Answer 20

In the answer choices it looks like this though \[\frac{ \pi }{ 2 }\]

Answer 21

practice makes perfect

Answer 22

Lol you're right

Answer 23

now you are proficient in how to find the amplitude and period

Answer 24

lol. Good job !

Answer 25

Oooh yay... thank you...
so then.... the amplitude is -6?

Answer 26

well the amplitud is always greater than 0, i mean positive

Answer 27

So it can NEVER be negative?

Answer 28

cause is the absolute value of A, that means how far is from the cero, an therfore

Answer 29

any -n or n number is always n units away from cero

Answer 30

What's cero? Does that mean zero o.o

Answer 31

you're right never could be negative, all because of the absolute value |A|

Answer 32

So the amplitude is 6 units away from 0?

Answer 33

That's right

Answer 34

So this is the overall answer?
http://awesomescreenshot.com/0492empmbb

Answer 35

HOw did you do that ? lol awesome, yeah you got it !

Answer 36

XD it's just a screenshot and thank you so much

Answer 37

lol ok. you're welcome and could keep improving if you practice a little bit more ;)

Answer 38

Lols I'll keep that in mind ^-^