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2y = xm + ( √(w + 2gm) ) / {w}^(2)

make 'm' the subject of the formula


User Buschtoens
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1 Answer

4 votes

Answer:

m = -(2g - 4xy)/2x²w⁴ + √((2g - 4xy)² - 4*(x²w⁴)*(4y²w⁴ - w))/2x²w⁴

Explanation:

2y= xm + √(w + 2gm) ÷ w^2

multiply all through by w²

2yw² = xm(w²) + √(w + 2gm)

rearranging

√(w + 2gm) = 2yw² - xmw²

square both sides

w + 2gm = (2yw² - xmw²)²

w + 2gm = (2yw² - xmw²)*(2yw² - xmw²)

w + 2gm = 4y²w⁴ - 2yxmw⁴ - 2yxmw⁴ + x²m²w⁴

collecting like terms

(x²w⁴)m² + (2g - 4yxw⁴)m + (4y²w⁴ - w). = 0

This seems to have been transformed to a quadratic equation

so we solve the quadratic equation by formula taking m as the variable

For simplicity, put

x²w⁴ = a

2g - 4xy = b

4y²w⁴ - w = c

we have

am² + bm + c = 0

solving the quadratic by formula

(-b + √(b² - 4ac))/2a. (taking the positive part)

-b/2a +√(b² - 4ac)/2a = m

substituting back

x²w⁴ = a

2g - 4xy = b

4y²w⁴ - w = c

m = -(2g - 4xy)/2x²w⁴ + √((2g - 4xy)² - 4*(x²w⁴)*(4y²w⁴ - w))/2x²w⁴

User Macsupport
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