Find the exact values of sinu2 cosu2 and tanu2 using the hal
Find the exact values of sin(u/2), cos(u/2), and tan(u/2) using the half-angle formulas
cot u = 2, pi<u<3pi/2
Sin(u/2)=
cos(u/2)=
tan(u/2)=
Solution
cot u=2
Here adjacent=2 and opposite=1
hypotenuse=sqrt(4+1)=sqrt5
And in third quadrant cos in negative
Therefore cos u=-2/sqrt5
sin u/2=sqrt(1-cos u)/2 = sqrt(1+2/sqrt5)/2=1/10(sqrt(5+2sqrt5)10)
cos u/2= sqrt(1+cos u)/2 = -sqrt(1-2/sqrt5)/2=1/10(sqrt(5-2sqrt5)10)
tan u/2=sin u/2/cos u/2= -sqrt((5+2sqrt5)/(5-2sqrt5))
