Question #6df80

1 Answer
Jan 16, 2017

sin2theta=sqrt3/2
cos2theta=1/2

Explanation:

sintheta=1/2
Draw an equilateral triangle and cut it in half to give a right angle triangle with sides in the ratio 1:2:sqrt3 ( the hypotenuse is 2 and Pythagoras gives the third side assqrt3
From this you can see that the angle whose sign is 1/2 is 30 degrees if theta =30 then 2theta=60 degrees
From the same triangle we get sin60 and cos60