To prove that f is continuous at p, we need to show that for any ε > 0, there exists δ > 0 such that |x - p| < δ implies |f(x) - f(p)| < ε.
Given that |f(x) - f(p)| ≤ M|g(x) - g(p)| for all x, we can rewrite this as |f(x) - f(p)|/|g(x) - g(p)| ≤ M for all x ≠ p.
Since g is continuous at p, we know that for any ε > 0, there exists δ > 0 such that |x - p| < δ implies |g(x) - g(p)| < ε/M.
Now, let's consider the expression |f(x) - f(p)|/|g(x) - g(p)|. If we assume that |x - p| < δ, then we can use the property of g being continuous at p to state that |g(x) - g(p)| < ε/M.
Therefore, we have |f(x) - f(p)|/|g(x) - g(p)| ≤ M, which implies |f(x) - f(p)| < M|g(x) - g(p)| < M(ε/M) = ε.
This shows that for any ε > 0, there exists δ > 0 such that |x - p| < δ implies |f(x) - f(p)| < ε, proving that f is continuous at p.
Therefore, if g is continuous at p, then f is also continuous at p.
Answer: f is continuous at p.