Question

1. If sin x=
2/3
find the value of cos 2x.

Answer 1

Answer:

cos2x= 1-1/2=1/2

Step-by-step explanation:

We have the identity

cos

2

x

=

1

−

2

sin

2

x

Hence as

sin

x

=

2

4

,

cos

2

x

=

1

−

2

sin

2

x

=

1

−

2

(

2

4

)

2

=

1

−

2

×

2

×

2

4

×

4

=

1

−

1

2

=

1

2