Answer :

Identity:

sin θ / cos θ = tan θ

In the triangle from theta, the adjacent side is denoted as x, the opposite side is denoted as y and the hypotenuse is h.

So, we can create the identities for the trig functions using the specifics denotations.

sin θ = y/h

cos θ = x/h

tan θ = y/x

Now we can set up the equation to be:

y/h ÷ x/h = y/x

When we divide, we take the reciprocal of the 2nd term and multiply it with the 1st term.

y/h × h/x = y/x

It becomes:

yh/hx = y/x

We can cancel out the h since it is present in both the numerator and denominator.

Leaving us with:

y/x = y/x

Proving the tan θ identity.