1. Direct variation y varies directly with x squared
Write an equation:
Y =kx^2
If x doubles then what happens to y?
Doubles ^2 (doubles squared) = 4 times bigger

2. If m varies directly with n cubed
Write an equation:
M= kn^3
If n doubles what happens to M?
Doubles^3 (doubles cubed) = 8 times bigger

3. L varies directly with W squared.
Write an equation
L = k W^2
If w is cut in half what happens to L?
½ squared ( ½ ^2) = 1/4th as big
If w is cut in 1/3 what happens to L?
1/3 squared (1/3 ^2) or 1/9th as big

4. W varies directly with T to the 4th
Write an equation:
W = 3T^4
If T doubles what happens to W?
Doubles ^4 = 16 times as big.
If T is cut in half what happens to W?
½ ^4 = 1/16th as big

5. R varies inversely with Q
Write an equation
R = K/Q
If q doubles what happens to R?
Doubles ^1 = two times smaller or divided by 2
If q triples what happens to R?
- Triples ^1 so 3 times smaller or divided by 3

6. U varies inversely with F cubed
Write an equation:
U = k/F^3
If F doubles what happens to U?
Doubles ^3 = divided by 8 or 8 times smaller
If F triples what happens to U?
Triples ^3 so divided by 27 or 27 times smaller

7. H varies inversely with J squared
Write an equation:
H = 3/J^2
If J is cut in half what happens to H?
½ ^ 2 so divided by ¼ (alg. says dividing by a fraction = multiplying by reciprocal so…) mult. by 4 or 4 times bigger
If J is cut in 1/3 what happens to H?
1/3 ^ 2 so divided by 1/9 (not reduced) so…. Multiplied by 9 or 9 times bigger.