We can also use the triangle inequality to us find bounds on functions. the triangle inequality tells us that |f(x) + g(x)| ≤ |f(x)| + |g(x)|. a) use the triangle inequality, together with the fact that |ab| = |a| ⋅ |b| to show that |f(x) − g(x)| ≤ |f(x)| + |g(x)|. b) use the triangle inequality to find a bound for f(x) = x 3 − 7x 2 + 3x − 5 on the interval [−2, 1]. be careful to justify all of your steps.