does anybody know how 1.04(cosA)^2 + 0.2(cosA) -0.75 = 0 become (cosA)^2 + 0.192(cosA) - 0.721 = 0

Are you kidding?

1.04 ( cos A )² + 0.2 ( cos A ) - 0.75 = 0

Divide both sides by 1.04

1.04 ( cos A )² / 1.04 + 0.2 ( cos A ) / 1.04 - 0.75 / 1.04 = 0 / 1.04

( 1.04 / 1.04 ) ∙ ( cos A )² + ( 0.2 / 1.04 ) ∙ ( cos A ) - 0.75 / 1.04 = 0

1 ∙ ( cos A )² + ( 0.2 / 1.04 ) ∙ ( cos A ) - 0.75 / 1.04 = 0

( cos A )² + 0.19231 ( cos A ) - 0.72115 = 0

approx.

( cos A )² + 0.192 ( cos A ) - 0.721 = 0

Magic math.

To understand how the equation 1.04(cosA)^2 + 0.2(cosA) - 0.75 = 0 becomes (cosA)^2 + 0.192(cosA) - 0.721 = 0, let's break it down step by step:

1. Start with the given equation: 1.04(cosA)^2 + 0.2(cosA) - 0.75 = 0

2. Now, let's try to eliminate the decimal point in the coefficient 1.04 by multiplying the entire equation by 100:

100 * [1.04(cosA)^2 + 0.2(cosA) - 0.75] = 100 * 0

Simplifying, we get: 104(cosA)^2 + 20(cosA) - 75 = 0

3. Next, let's deal with the coefficient 104. To simplify the equation, divide the entire equation by 104:

(1/104) * [104(cosA)^2 + 20(cosA) - 75] = (1/104) * 0

Simplifying, we get: (cosA)^2 + (20/104)(cosA) - (75/104) = 0

4. Now, let's simplify the fraction (20/104) by dividing both the numerator and denominator by their greatest common divisor, which is 4:

(cosA)^2 + (5/26)(cosA) - (75/104) = 0

5. Simplifying further, we have:

(cosA)^2 + 0.192(cosA) - 0.721 = 0

Thus, the equation 1.04(cosA)^2 + 0.2(cosA) - 0.75 = 0 becomes (cosA)^2 + 0.192(cosA) - 0.721 = 0 after simplification and elimination of decimals.