Question

cos^-1(15/17) + 2 tan^-1(1/5) =
a) pi/2;
b)cos^-1(171/221)
c)pi/4;

Answer 1

2tan(inv) X= cos(inv)[(1-x2)/(1+x2)]
convert then apply addition rule of cosine (inv) function

Answer 2

got it...

Answer 3

or do you need an explanation???

Answer 4

no il try on my own

Answer 5

fine...

Answer 6

hey, im getting in decimals.

Answer 7

hey @Sarkar - can you explain now please?

Answer 8

did you get my formula???