I Find the area enclosed by the curve x = 58th, y = 25in(), 0 S t S 21:. Write the exact answer. Do not round. Find the equations of any horizontal tangent lines to the curve x = if2 t, y = 4 + 712. Write the exact answer. Do not round. Separate multiple answers with a comma. If there are no points where the curve has a horizontal tangent line, write None for your