2sin45/4°=√2-√2+√2 prove this ?
( the first root is the main root.the second and the third root is under the main root).
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1 Answers
62Lets take this way..
cos 2 (A/2) = √(1+cos A) / 2
So you can find cos 45/2
Then find cos 45/4 using the same thing again...
Then finally find the value of sin 45/2 using
sin2(45/4) + cos2(45/2) = 1
Here at each step, it is important to note that you will use only the positive solution because the angle is in 1st quadrant all the time and sin or cos of both is +ve :)
