The relation of quotient of two trigonometric ratios with another trigonometrical ratio at an angle is called quotient trigonometrical identity.
Trigonometric ratios can form another trigonometric ratio by the quotient of them. Quotient trigonometric ratios are mainly used to express the ratio of trigonometric ratios into another trigonometric as the quotient of them and vice-versa.
In trigonometry, there are six trigonometric ratios but sine and cosine can only form tangent and cotangent from their quotients.
The ratio of trigonometric functions sine to cosine at an angle in a right angled triangle is equal to another trigonometric function tangent at same angle.Learn Proof
The ratio of trigonometric functions cosine to sine at an angle in a right angled triangle is equal to another trigonometric function cotangent at same angle.Learn Proof