Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
remaining cards
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

Module 4

Variation and Problem Solving

Direct Variation Equation y=kx
Inverse Variation Equation y=k/x
Direct Variation: y=12 x=4 y=kx ; 12=4k ; k=(12/4)=3 ; y=3x
Direct Variation y=4 x=6 y=kx ; 4=6k ; k=(4/6)=2/3 ; y=(2/3)x
Direct Variation y=2 x=1/2 y=kx ; 2=(1/2)k ; k=(2/(1/2))=4 ; y=4x
Inverse Variation y=10 x=15 y=k/x ; 10=k/15 ; k=(10*15)=150 ; y=150/x
Inverse Variation y=2 x=12 y=k/x ; 2=k/12 ; k=(2*12)=24 ; y=24/x
Inverse Variation y=1/5 x=1/2 y=k/x ; 1/5=k/(1/2) ; k=(1/5*1/2)=1/10 ; y=(1/10)/x
Joint Variation y=kxz
a product weighs (y) 100 lbs when it is 8' high (h) by 2'wide (w) . If the weight varies jointly with height and width, what will a 10' high8 by 10' wide piece weigh? y=khw ; 100=k(8)(2) ; 100=16k ; k=6.25 ; y=(6.25)(10)(10) ; y=625
y varies jointly and directly with x and Y the square of w and inversely of z. y=100 when x=10,w=5 and z=12. find y when x=2,w=9 and z=10? y=(kxw^2)/z ; 100=(k(10)(5^2))/12 ; k=4.8 ; y=((4.8)(2)(9^2))/10 ; y=77.76
Y is directly proportional to the square of X: y=2 x=8 Y=kx^2 ; 2=k(8)^2 ; k=1/32 ; Y=(1/32)x^2
Y is inversely proportional to the cube of X : Y=3 X=5 Y=k/x^3 ; 3=k/(5)^3 ; k=375 ; Y=375/x^3
Created by: doug418