Question

if cos x is equal to minus 3 upon 5 and X is in III quadrant then find the value of cos x upon 2,sin x upon 2,sin 2 x​

Answer 1

Answer:

cosx

Step-by-step explanation:

cosx=-3/5

cos2x = 2cos square(x) − 1

cos square(x)= (cos2x+1)/2

replace 2x with x,

cos(x/2)= √((1+cosx)/2)

cos(x/2) = √(1-3/5)/2

cos(x/2) = √1/5

sinx =√1-cos square (x)

sinx =-4/5

sin2x = 2 sinxcosx

=2*(-4/5)*(-3/5)

=24/25

sin(x/2) = √(1-cos square (x/2))

sin(x/2) = 2/√5