FunctionHard
Question
If f(x) = cos(ln x), then f(x) f(y) -
has the value
has the valueOptions
A.-1
B.1/2
C.-2
D.None of these
Solution
f(x) = cos (ln x)
f(x) . f(y) = cos(ln x) . cos (ln y)
f (x/y) + f(xy) = cos (ln x - lny) + cos (ln x + ln y)
∴ f(x) . f(y) -
= cos (ln x) cos (ln y) - 
[2 cos(lnx) cos (ln y) = 0
f(x) . f(y) = cos(ln x) . cos (ln y)
f (x/y) + f(xy) = cos (ln x - lny) + cos (ln x + ln y)
∴ f(x) . f(y) -
= cos (ln x) cos (ln y) - [2 cos(lnx) cos (ln y) = 0Create a free account to view solution
View Solution FreeMore Function Questions
If S is the set of all real x such that is positive, then S contains...If the domain of the function $f(x) = \sin^{- 1}\left( \frac{5 - x}{3 + 2x} \right) + \frac{1}{\log_{e}g( + 0}$ is $( - ...Given f(x) = log and g(x) = , then (fog) (x) equals -...Let f : [-1, 2] → [0, ∞) be a continuous function such that f(x) = f (1 - x) for all x ε [-1, 2]. Let R...Function f : R → R , f(x) = x |x| is -...