# Thread: i need to generate a formula

1. ## i need to generate a formula

should be basic, here's my challenge:
I need formula to calulate a descending value when a know value is entered eg:

input output
1.40 = 27.07
1.41 = 27.06
1.42 = 27.05
1.43 = 27.04
and on and on

In other words the known(input) value increase in .01 increments, then the output value decreases by .01.
What's the formula that may be applied for this?
Thanks and kudos to whomever can help with this.

2. Originally Posted by Gabor1972
should be basic, here's my challenge:
I need formula to calulate a descending value when a know value is entered eg:

input output
1.40 = 27.07
1.41 = 27.06
1.42 = 27.05
1.43 = 27.04
and on and on

In other words the known(input) value increase in .01 increments, then the output value decreases by .01.
What's the formula that may be applied for this?
Thanks and kudos to whomever can help with this.
$\displaystyle m=\frac{y-y_1}{x-x_1}=\frac{27.07-27.06}{1.4-1.41}=\frac{.01}{-.01}=-1$

$y-y_1=m(x-x_1)$