Question

if cos x=4/5 and x is acute, then find the value of sin 2x​

Answer 1

Answer:

sin 2x=24/25

Step-by-step explanation:

cos x=opp/hyp=4/5

apply pythagoras theorem :

hyp^2= adjacent ^2+opposite ^2

adjacent=(hyp ^2- opp^2)^1/2

adj=(25-16)^1/2=9^1/2=3

sin x = 3/5

sin 2x= 2sin x cos x

= 2× 3/5×4/5

= 24/25