Question

1. If y varies inversely as x and when y=2, x=1.6,
a. find y when x=0.8,
b. find x when y=4

Answer 1

Answer:

The answer is y=2

The statement is expressed as y∝1x

inverse means 1variable

To convert to an equation introduce k, the constant of variation.

y=k×1x

⇒y=kx

To find k use the given condition that y = 8 whenx = 48=k4

⇒k=4×8=32

⇒ equation is

¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯∣∣∣22y=32x22∣∣∣−−−−−−−−−−−−

x=16→y=3216

⇒y=2 when x=16