What is [tex]$\tan 45^{\circ}$[/tex]?

A. 1
B. [tex]$\frac{1}{\sqrt{2}}$[/tex]
C. [tex][tex]$\sqrt{2}$[/tex][/tex]
D. [tex]$\frac{1}{2}$[/tex]



Answer :

To determine the value of [tex]\(\tan 45^\circ\)[/tex], we start by knowing the fundamental definition of the tangent function for an angle in right triangle trigonometry. The tangent of an angle [tex]\(\theta\)[/tex] is given by the ratio of the length of the opposite side to the length of the adjacent side:

[tex]\[ \tan \theta = \frac{\text{opposite}}{\text{adjacent}} \][/tex]

For a [tex]\(45^\circ\)[/tex] angle in a right triangle, it's helpful to consider an isosceles right triangle where the two legs are equal in length. Let's assume the legs are both of length 1 unit.

So, in an isosceles right triangle with both legs having a length of 1 unit:

[tex]\[ \tan 45^\circ = \frac{\text{opposite leg}}{\text{adjacent leg}} = \frac{1}{1} = 1 \][/tex]

Let's confirm we are on the same page with the trigonometric values for this key angle. To convert [tex]\(45^\circ\)[/tex] to radians (if you're more comfortable working in radians), recall that:

[tex]\[ 45^\circ = \frac{\pi}{4} \text{ radians} \][/tex]

Using the unit circle, the coordinates at [tex]\(\frac{\pi}{4}\)[/tex] radians or [tex]\(45^\circ\)[/tex] are [tex]\((\frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}})\)[/tex]. Therefore,

[tex]\[ \tan 45^\circ = \frac{\sin 45^\circ}{\cos 45^\circ} = \frac{\frac{1}{\sqrt{2}}}{\frac{1}{\sqrt{2}}} = 1 \][/tex]

Finally, considering the numerical result:

[tex]\[ \tan 45^\circ \approx 0.9999999999999999 \][/tex]

which is very close to 1. Hence, the most precise answer matching the value of [tex]\(\tan 45^\circ\)[/tex] is:

[tex]\[ \boxed{1} \][/tex]