## Thomas' Calculus 13th Edition

$-2\leq t\leq 4,\qquad$ or, $t\in [-2,4]$
Use properties from the table 'Absolute Values and Intervals". Applying Property 6: $|x|\leq a\quad\Leftrightarrow\quad -a\leq x\leq a, \quad$ for a = positive number We have: $-3\leq t-1\leq 3\qquad$ add 1 to all parts: $-2\leq t\leq 4$ This is a closed interval, $[-2,4]$ (see table: "Types of intervals".)