Question

\[cos^-1\frac{4}{5} + cos^-1\frac{12}{13}=cos^-1\frac{33}{65}\] when the inverse function takes principal range.

Answer 1

@experimentX

Answer 2

I think it is to show that the LHS is equal to the RHS.

Answer 3

yes ... try taking sin() of whole thing on both sides.

Answer 4

did you copy the question correctly? the wolframalpha says it's false.
http://www.wolframalpha.com/input/?i=arcsin%283%2F4%29+%2B+arctan%281%2F7%29+%3D+pi%2F4

Answer 5

Then my teacher has given it wrong. :D But there are 3 more questions given. :(

Answer 6

I checked another question and the wolfram alpha says it is true. Can you help me solve it?

Answer 7

sure

Answer 8

I changed the question. :)