1. **State the problem:** We are given two functions:
$$f(x) = 3x^4$$
$$g(x) = 2 \cdot 5^x$$
We need to determine which statements about these functions are true.
2. **Understand the functions:**
- $f(x) = 3x^4$ is a polynomial function of degree 4, which grows quickly for large $|x|$.
- $g(x) = 2 \cdot 5^x$ is an exponential function with base 5, which grows faster than any polynomial as $x \to \infty$.
3. **Compare values at specific points:**
- At $x=0$:
$$f(0) = 3 \cdot 0^4 = 0$$
$$g(0) = 2 \cdot 5^0 = 2 \cdot 1 = 2$$
So, $g(0) > f(0)$.
- At $x=1$:
$$f(1) = 3 \cdot 1^4 = 3$$
$$g(1) = 2 \cdot 5^1 = 10$$
So, $g(1) > f(1)$.
- At $x=2$:
$$f(2) = 3 \cdot 2^4 = 3 \cdot 16 = 48$$
$$g(2) = 2 \cdot 5^2 = 2 \cdot 25 = 50$$
So, $g(2) > f(2)$.
- At $x=3$:
$$f(3) = 3 \cdot 3^4 = 3 \cdot 81 = 243$$
$$g(3) = 2 \cdot 5^3 = 2 \cdot 125 = 250$$
So, $g(3) > f(3)$.
4. **Behavior for large $x$:**
Since $g(x)$ is exponential and $f(x)$ is polynomial, for very large $x$, $g(x)$ will always be greater than $f(x)$.
5. **Behavior for negative $x$:**
- For negative $x$, $f(x) = 3x^4$ is always positive because $x^4$ is positive.
- For $g(x) = 2 \cdot 5^x$, since $5^x$ decreases as $x$ becomes more negative, $g(x)$ approaches 0 but remains positive.
6. **Summary:**
- $g(x)$ is greater than $f(x)$ for $x \geq 0$.
- Both functions are positive for all real $x$.
**Final conclusion:** The statement "$g(x)$ is greater than $f(x)$ for all $x \geq 0$" is true.
Compare Functions 6E32Fb
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