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Correct ± √(1+x)/2 = cos Θ/2

Step-by-step explanation:

We know it is:

cos2Θ = cos²Θ - sin²Θ,   according to this:

cosΘ = cos²Θ/2 - sin²Θ/2 => cosΘ = cos²Θ/2 - (1 - cos²Θ/2) =>

cosΘ = cos²Θ/2 - 1 + cos²Θ/2 => 1 + cosΘ = 2 cos²Θ/2 =>

cos²Θ/2 = (1 + cosΘ)/2 => cos Θ/2 = ±√(1 + cosΘ)/2 =>

±√(1 + cosΘ)/2 = ± √(1+x)/2 = cos Θ/2

God is with you!!!

109 is the nearest whole number/final answer! : )

144.50

step-by-step explanation:

21.5 x 13.4=288.10 divide by 2