Question

find the principal solutions:- cos x=1​

Answer 1

Step-by-step explanation:

cosx=(

3

π

) and cos x = cos(2π−

3

π

) =cos(

3

5π

) such that 0<

3

π

<2π and 0<

3

5π

<2π

∴ The required principal solutions are x=

3

π

and x=

3

5π