Question

If 4 sin-1x + cos2x = , then : X

Answer 1

Answer:

Hope it helps you

Step-by-step explanation:

We have 4sin

4

x+cos

4

x=1

⇒4sin

4

x=1−cos

4

x=(1−cos

2

x)(1+cos

2

x)=sin

2

x(2−sin

2

x)

⇒sin

2

x[5sin

2

x−2]=0

⇒sinx=0 or sinx=±

5

2

⇒x=nπ or x=nπ±sin

−1

5

2

,(n∈Z)