Question
Question: If cos<sup>–1</sup> \(\frac { x } { 2 }\) + cos<sup>–1</sup> \(\frac { y } { 3 }\) = \(\frac { \pi...
If cos–1 2x + cos–1 3y = 6π , then value of 4x2 – 23xy +
is
A
43
B
21
C
41
D
None of these
Answer
41
Explanation
Solution
cos–1 (2x) + cos–1
= 6π
cos–1 [6xy−1−4x21−9y2] = 6π
=
. 
23xy + 41
