Question

cos -1 (-x), |x| ≤ 1 is equal to

Answer 1

Step-by-step explanation:

cos -1 (-x), |x| ≤ 1 is equal to

Let cosA=x then cos(π−A)=−cosA=−x

 

Hence, cos−1x=A 

cos−1(−x)=π−A 

Adding them,

cos−1x+cos−1(−x)=A+π−A⇒cos−1x+cos−1(−x)=π⇒cos−1(−x)=π−cos−1(x)

Answer 2

Answer:

cos -1 (-x), lxl < 1 is equal to

Let cosA=x then coz (-A) =.-cos A =x

Hence, cos -1x=A

cos-1(-x)=-A

Adding them

→cos -1 (-x)= - cos-1(x)