Question

complete the the table below for the fucntion
y=20/x^2 for 2< or equal to x < or equal to 7.

x 2 3 4 5 6 7
y ? 2.2 1.3 ? 0.6 ?

When x=2, then y=4
When x =5, y =0.8
When x=7, then y=0.41 is this correct?
The value of y when x=4.5, is the ans=4.4?
And how do find the value of x when y is=3.5?

Answer 1

when x=2, y = 20/4 = 5
when x=4.5, y = 20/20.25 = .987654321.. (interesting sequence of digits !!)

so when y = 3.5
20/x^2 = 3.5
cross-multiply
x^2 = 20(3.5) = 70
x = √70 = 8.3660...

You don't seem to be consistent with the number of decimals you carry,
for x=3 your rounded y to one decimal but
for x=7 you rounded y to 2 decimals.
Why?