Question

sinx=3/5

Find sin 2x, cos 2x, and tan 2x from the given information in quadrant I

Answer 1

you can find the values of sin , cos and tan x from this right angled triangle:

Answer 2

eg cos x = 4/5

Answer 3

now to find sin 2x use the identity

sin 2x = 2 sin x cos x

and cos 2x = 2 cos^2 x - 2

Answer 4

how do I find sin 3/5 on the unit cirlcle? is that how I'm supposed to get it?

Answer 5

* thats cos 2x = 2 cos^2 x - 1

Answer 6

the 3-4-5 right angled triangle gives you sin x = opp/hyp = 3/5

Answer 7

oh ok

Answer 8

to get tan 2x you use the identity tan 2x = sin 2x / cos 2x