Q.

Considering only the principal values of the inverse trigonometric functions, the value of

32cos-122+π2+14sin-1(22π2+π2)+tan-1(2π)  is ________.                         [2022]


Ans.

(2.36)

[Let, cos-122+π2=t=tan-1(π2)]

{Similarly for sin-1(22π2+π2)}

Now, we have

32tan-1(π2)+14tan-1(22ππ2-2)+tan-1(2π)

=π2+12tan-1(π2)-14tan-1(22π2-π2)

=π2+12tan-1(π2)-14tan-1(2(π2)1-(π2)2)

=π2+12tan-1(π2)-14(-π+2tan-1(π2))

=π2+π4=3π4=2.36