" 9."cos^(-1)((-1)/(2))

The value of cos^(-1){(1)/(sqrt(2))(cos((9 pi)/(10))-sin((9 pi)/(10)))}

If y=cos^(-1)((9-x^(2))/(9+x^(2))), then y^(1)(-1) is equal to

Prove that. tan^(-1)((1)/(4)) +tan^(-1)((2)/(9)) =(1)/(2) cos^(-1) ((3)/(5)) .

cos^(-1)((x^(2))/(6)+sqrt(1-(x^(2))/(9))sqrt(1-(x^(2))/(4)))=cos^(-1)((x)/(3))-cos^(-1)((x)/(2)) hold for all x belonging to

Find the value of the following inverse trigonometric expression: cos^(-1)(1/(sqrt(2))("cos"(9pi)/10-"sin"(9pi)/10))

Find the value of the following inverse trigonometric expression: cos^(-1)(1/(sqrt(2))("cos"(9pi)/10-"sin"(9pi)/10))

Prove that: tan^(-1)((1)/(4))+tan^(-1)((2)/(9))=(1)/(2)cos^(-1)((3)/(5))

The value of cos^(-1){1/(sqrt(2))("cos"(9pi)/10-"sin"(9pi)/10)} is