Sign in
Please select an account to continue using cracku.in
↓ →
Let f and g be two functions defined by $$f(x) = \mid x + \mid x \mid \mid$$ and $$g(x) = \frac{1}{x}$$ for $$x \neq 0$$. If $$f(a) + g(f(a)) = \frac{13}{6}$$ for some real a, then the maximum possible value of $$f(g(a))$$ is:
Correct Answer: 6
Given that f(a) + g(f(a)) = $$\dfrac{\ 13}{6}$$
f(a) + $$\dfrac{\ 1}{f\left(a\right)}$$ = $$\dfrac{\ 13}{6}$$
$$6(f(a))^2-13\left(f\left(a\right)\right)+6\ =\ 0$$
f(a) = $$\dfrac{13\pm\sqrt{13^2-24\left(6\right)\ }\ }{2\times6}$$
this implies , f(a) = $$\ \dfrac{\ 3}{2}\ (or)\ \dfrac{\ 2}{3}$$
Given that f(a) = |a+|a||
if $$a\le0\ $$, f(a) = |a-a| = 0
else if $$a\ge\ 0$$ , then f(a) = 2a.
Therefore , 2a = $$\ \dfrac{\ 3}{2}\ (or)\ \dfrac{\ 2}{3}$$
that is, a = $$\ \dfrac{\ 3}{4}\ (or)\ \dfrac{\ 1}{3}$$
g($$\dfrac{\ 3}{4}$$) = $$\dfrac{\ 4}{3}$$
g($$\dfrac{\ 1}{3}$$) = $$\dfrac{\ 3}{1}$$
Therefore f(g(a)) = $$\dfrac{\ 8}{3}$$ or 6.
Maximum value is 6.
Click on the Email ☝️ to Watch the Video Solution
Create a FREE account and get:
Crack IPMAT 2026 with Cracku
Educational materials for IPMAT and IIMB UG preparation
Ask our AI anything
AI can make mistakes. Please verify important information.
AI can make mistakes. Please verify important information.