1. I have a calculation in a procedure:

CD = (E - (2 * .286 * A)) / 2 + (M * A / PI) / 2

E A & M are given.

but I have situations where I need to calculate A when CD E & M are known.

Can someone rewrite the equation for me please, its making my brain hurt!

2. I hope I have not made any silly mistakes...

CD = (E-(2 * .286 * A)) /2 + (M *A/PI)/2

2 * CD = E-(2 * .286 * A) + (M *A/PI) Multiply both sides by 2

= E- A*(2 * .286) + A*(M *1/PI)

= E-A*((2 * .286 ) - (M *1/PI)) Bring the common factor of A to the front

(2*CD) -E = -A*((2 * .286 ) - (M *1/PI)) subtract E from both sides

E-2*CD = A*((2 * .286) - (M * 1/PI)) multiply both sides by -1

A = (E- 2*CD)
/ ((2 * .286) - (M * 1/PI))

3. Originally Posted by weyrman
I have a calculation in a procedure:

CD = (E - (2 * .286 * A)) / 2 + (M * A / PI) / 2

E A & M are given.

but I have situations where I need to calculate A when CD E & M are known.

Can someone rewrite the equation for me please, its making my brain hurt!
As an alternative, you could use the Solver function to give you the value of A that gives the value of CD you require.

Think of it as en 'engineering' solution rather than a mathematical one.

4. John,

Many thanks, your maths was spot on!

Gfamily,

I've never played with solver before but thanks for the suggestion.

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