C3 half angle of TAN proof!Watch
and Cos1/2x= +/- (square root) ((1+cosx)/2)
Then how does tan1/2x become sinx/(1+cosx)?
Could someone explain the steps of the proof please. Thanks
just wondering why the "plus or minus" is not on the tan ?
Consider when sin(x) is positive - it's exactly when x is between 0 and pi, or 2pi and 3pi, or…
And 1+cos(x) is always positive.