Question

The displacement from equilibrium of an oscilating weight suspended by a spring given by y(t)=2cos8t where y is the displacemnt in centimeters and t is time in seconds. Find the displacment when t=.45

Answer 1

substitute .45 for t in 2cos8t and solve
you are solving y(.45) =2cos8t

Answer 2

will give y value when t=.45 seconds

Answer 3

i then get 1.9961 cm

Answer 4

teacher said this was wrong.

Answer 5

let me calculate it

Answer 6

That's not what I get. (1.9961 cm is not correct)

Answer 7

are you using a calculator?

Answer 8

yes a ti-89

Answer 9

I get -1.79

Answer 10

got*

Answer 11

enter 2cos(8*.45)

Answer 12

give a fish they can eat for a day, teach to fish...

Answer 13

i did and got 1.9961

Answer 14

no negative sign?

Answer 15

make sure you are in radian mode

Answer 16

ahh

Answer 17

degree mode will give you wrong answer for that one

Answer 18

how do u know which mode to go in? it always gets me

Answer 19

i still struggle with that

Answer 20

haha shoot

Answer 21

hold on

Answer 22

Use google calculator

Answer 23

i would like to know out of my head tho.

Answer 24

for tests