Question

If a = 3 Cos 2 ; and b = 3Sin 2 +1; then find a+b

Answer 1

Step-by-step explanation:

Given,

32tan

8

θ=2cos

2

α−3cosα...............(i)

3cos2θ=1

This gives

1+tan

2

θ

1−tan

2

θ

=

3

1

So, tan

2

θ=

2

1

Given equation (i) becomes

32(tan

2

α)

4

=2cos

2

α−3cosα

⇒32×

16

1

=2cos

2

α−3cosα

⇒2=2cos

2

α−3cosα

⇒2cos

2

α−3cosα−2=0

⇒2cos

2

α−4cosα+cosα−2=0

⇒2cosα(cosα−2)+1(cosα−2)=0

⇒(2cosα+1)(cosα−2)=0

So, cosα=−

2

1

or cosα=2

∵cosα



=2

∴cosα=−

2

1

⇒α=

3

2π

So. general solution is α=2nπ±

3

2π

Answer 2

Answer:

If a = 3 Cos 2 ; and b = 3Sin 2 +1; then find a+b

Step-by-step explanation: