x = ky^3
1 = k*2^3
k = 1/8
now just crank out the answers
if x is directy proportinal to y cube and y=2 when x= 1, (a) find an equation connecting x and y. (b) find the value of x when y = 1 (c) find the value of y when x=108.
2 answers
x ∝ y^3 ---> x = ky^3 , where k is a constant
given: y=2 when x=1
1 = 8k
k = 1/8
x = (1/8)y^3
when y = 1
x = (1/8)(1^3) = 1/8
when x = 108
108 = (1/8)y^3
864 = y^3
y = appr 9.5244
given: y=2 when x=1
1 = 8k
k = 1/8
x = (1/8)y^3
when y = 1
x = (1/8)(1^3) = 1/8
when x = 108
108 = (1/8)y^3
864 = y^3
y = appr 9.5244