Question

r=4" align="absmiddle" class="latex-formula">

Answer 1

Answer:

$r = \sqrt[3]{\frac{4}{3} }$

Step-by-step explanation:

$-r + (3r^2 + 1)r = 4\\-r + 3r^3 + r = 4\\3r^3 = 4\\r^3 = \frac{4}{3} \\\\r = \sqrt[3]{\frac{4}{3} }$