Question #6df80

1 Answer
Jan 16, 2017

sin2θ=32
cos2θ=12

Explanation:

sinθ=12
Draw an equilateral triangle and cut it in half to give a right angle triangle with sides in the ratio 1:2:3 ( the hypotenuse is 2 and Pythagoras gives the third side as3
From this you can see that the angle whose sign is 12 is 30degrees if θ=30 then 2θ=60degrees
From the same triangle we get sin60 and cos60