Question
Question: In its domain, f(x) = \(\frac{\sin^{–1}x}{\cot^{–1}x}\) is –...
In its domain, f(x) = cot–1xsin–1x is –
A
A increasing function
B
A strictly increasing function
C
A decreasing function
D
A strictly decreasing function
Answer
A strictly increasing function
Explanation
Solution
f '(x) = (cos–1x)21–x21×(cos–1x–sin–1x)×(–1–x21)
= 1–x2(cos–1x)2cos–1x+sin–1x = 1–x2(cos–1x)2π = + ve
= f '(x) > 0 st. Inc. function