Question

If sinA = 2/3 find cos A/2 =?
need help ASAP

Answer 1

HI!!

Answer 2

first find \(\cos(A)\)

Answer 3

then use
\[\cos(\frac{A}{2})=\sqrt{\frac{1+\cos(A)}{2}}\]

Answer 4

HOW to get cos A?

Answer 5

draw a triangle

Answer 6

there is a picture on an angle whose sine is \(\frac{2}{3}\)
find the third side via pythagoras

Answer 7

once you have the missing side, you know the cosine
let me know when you get it

Answer 8

Oh i get it ... i'll give it a try... with some other exercises

Answer 9

Waiting for lynfran's reply