Question

find the value of cos inverse cos 7pie by 6​

Answer 1

Answer:

You can write  

7

π

6

as  

(

π

+

π

6

)

Thus we can clearly see the angle falls in the third quadrant. And the cosine value in third quadrant is always negative.

Hence,  

cos

(

π

+

π

6

)

=

−

cos

(

π

6

)

coming back to the question  

cos

−

1

[

cos

(

7

π

6

)

]

=

cos

−

1

[

−

cos

(

π

6

)

]

=

π

−

cos

−

1

[

cos

(

π

6

)

]

=

π

−

π

6

=

5

π

6

Step-by-step explanation: