Question
Question: If sin<sup>–1</sup> x + sin<sup>–1</sup>y + sin<sup>–1</sup>z = \(\frac { 3 \pi } { 2 }\)and f(1) = ...
If sin–1 x + sin–1y + sin–1z = 23πand f(1) = 2, f(p +q) = f(p). f(q) " p, q Ī R, then
xf(1)+yf(2)+zf(3)x+y+z=
A
0
B
1
C
2
D
3
Answer
2
Explanation
Solution
– 2π £ sin–1 x £ 2π
\ sin–1 x + sin–1 y + sin– 1z = 23π
Ū sin–1 x = sin–1 y = sin– 1z = 2π
Ū x = y = z = 1
Also f(p + q) = f(p). f(q) " p, q Ī R …(1)
Given f(1) = 1
from (1),
F(1 + 1) = f(1). F(1) Ž f(2) =12 = 1
from (2), f(2 + 1) = f(2) . f(1)
Ž f(3) = 12. 1 = 13 = 1
Now given expression = 3 – 33 = 2