Answer
$\tan42^{\circ}15′$ = 0.9083
Work Step by Step
First we will convert $42^{\circ}15′$ to decimal degrees, let's break it as-
$42^{\circ}15′$ = $42^{\circ}$ + $15′$
Now on dividing 15′ by 60, we have the number of "decimal degrees" equivalent to 15′ (as $1^{\circ}$=60′)
Therefore
$42^{\circ}15′$ = $42^{\circ} + (\frac{15}{60})^{\circ}$
$42^{\circ}15′$ = $42^{\circ} + 0.25^{\circ}$
$42^{\circ}15′$= $42.25^{\circ}$
Now
Using calculator in degree mode-
$\tan 42.25^{\circ}$ = 0.9083360465
Rounding it to four places past the decimal point-
$\tan 42.25^{\circ}$ = 0.9083
Therefore-
$\tan42^{\circ}15′$ = 0.9083
