If Y varies inversely as the cube root of x. If y = 4 when x = 27, how do you find y when x = 8?

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Answer 1 · 2017-05-17T09:38:17

y = 6 when x = 8

If y varies inversely as the cube root of x then we can express this algebraically thus

#y = k*1/x^(1/3)#

Using the values # y = 4 # when # x = 27 #

We get # 4 = k / 27^(1/3 )#
# 4 = k /3 #

Therefore # k = 12 #

The relationship can now be fully expressed as # y = 12/x^(1/3 )#

Using this rule when # x = 8#

# y = 12 / 8^(1/3) = 12/2 = 6 #