Question 304573
Since I can not show a theta symbol, let X = theta

Given: {{{Cos(X) = Sin(X)*Cot(X)}}}
You need to know that {{{Cot(X) = (Cos(X))/(Sin(X))}}}
Then rewrite the equation
{{{Cos(X) = Sin(X)*(Cos(X))/(Sin(X))}}} The Sin(X)'s cancel out
{{{Cos(X) = cross(Sin(X))*(Cos(X))/cross((Sin(X)))}}}
{{{highlight(Cos(x) = Cos(x))}}}