Answer
$-\frac{3}{2}t^\frac{-7}{4}$
Work Step by Step
$2t^\frac{-3}{4}$
Differentiate using the power and constant multiple rule. Keep the constant, bring down the original power (n), and multiply by $t^{n-1}$
$2*(\frac{-3}{4})*t^\frac{-7}{4}$