Question

solve sinx/2,cosx/2 & tanx/2 of the following:-
(a)sinx=1/4 & x lies in second quadrant.

Answer 1

draw your triangle
the other side is √15

since we are in QII and sin is positive,

x = -√15
y = 1
r = 4
so, cosx = -√15/4

Now use those values to plug into your half-angle formulas.

Answer 2

Detail