Answer
The temperature on April 1 is $18.7^{\circ}F$
Work Step by Step
April 1 is day 91, so we can use $x = 91$ in the equation:
$T(x)=37~sin[\frac{2\pi}{365}~(x−101)]+25$
$T(91)=37~sin[\frac{2\pi}{365}~(91−101)]+25$
$T(91)=37~sin(-0.1721)+25$
$T(91)=37~[-sin(0.1721)]+25$
$T(91)=(37)(-0.1713)+25$
$T(91) = 18.7^{\circ}F$
The temperature on April 1 is $18.7^{\circ}F$