Question

2 cos x + 1 is equal to sin x​

Answer 1

Answer:

Correct option is

A

8

Using cosx=

1+tan

2

2

x

1−tan

2

2

x

,sinx=

1+tan

2

2

x

2tan

2

x

∴sinx+2cosx=1

⇒(

1+tan

2

2

x

2tan

2

x

)+2(

1+tan

2

2

x

1−tan

2

2

x

)=1

⇒3tan

2

2

x

−2tan

2

x

−1=0

⇒(3tan

2

x

+1)(tan

2

x

−1)=0

⇒tan

2

x

=1 or −

3

1

Now 7cosx+6sinx

=7(

1+tan

2

2

x

1−tan

2

2

x

)+6(

1+tan

2

2

x

2tan

2

x

)

When tan

2

x

=1⇒7cosx+6sinx=6

And when tan

2

x

=−

3

1

⇒7cosx+6sinx=2

Therefore sum of value of solution is 6+2=8

Step-by-step explanation:

I hope it's help you dear