Evaluate \(f(g(x))\)
🎥 Video Explanation
📝 Question
Given:
\[ g(x)=1+x-[x] \]
\[ f(x)= \begin{cases} -1, & x<0 \\ 0, & x=0 \\ 1, & x>0 \end{cases} \]
- (a) \(x\)
- (b) \(1\)
- (c) \(f(x)\)
- (d) \(g(x)\)
✅ Solution
🔹 Step 1: Understand \(g(x)\)
\[ x-[x] \in [0,1) \]
So:
\[ g(x)=1+(x-[x]) \in [1,2) \] —
🔹 Step 2: Apply \(f\)
Since \(g(x) \in [1,2)\), it is always:
\[ g(x) > 0 \]
—🔹 Step 3: Use Definition of \(f\)
For all positive inputs:
\[ f(g(x)) = 1 \] —
🔹 Final Answer
\[ \boxed{\text{Option (b): } 1} \]