Question

Find cos(x/2) when sin(x)=-12/13, and x is in
Quad III

Answer 1

make the coreesponding triangle to find cos(x) then use the half angle identity.

Answer 2

a=-6.93?

Answer 3

\(a =-\sqrt{13^2-11^2}\)

Answer 4

\(a = \sqrt{48}=\sqrt{16}\cdot\sqrt{3}=4\sqrt{3}\)

Answer 5

oops... \(a=-4\sqrt{3}\)