Simplify the expression by using a Double-Angle Formula or a Half-Angle Formula. square root over the entire fraction 1-cos(50 degrees) / 2

Answer 1

sin25 = sqr[(1-cos50)/2

.423 = sqr(.17861) = .423

the square root of the fraction (1-cos50)/2 = sin(50/2) = sin25

although the half angle formula has a plus

or minus sign, which means the solution would be

sin25

or -sin25

+ sin25

using the double angle formula

cos50 = cos^2(25) - sin^2(25) = 0.821 - 0.179 = 0.642, due to rounding approximations, it's actually closer to 0.643

cos50 = 0.6428

sqr[1-.6428)/2] = sqr(.3572/2) = sqr(.17851) = 0.4225 = 0.423 rounded up