To simplify the given expression sinA(cotA 3)(3cotA 1), we can break it down step by step.

Step 1: Simplify cotA 3
The expression cotA 3 represents the cotangent of angle A multiplied by 3. To simplify, we need to recall the definition of cotangent, which is equal to the cosine of an angle divided by the sine of the same angle. Therefore, we can rewrite cotA 3 as (cosA / sinA) * 3.

Step 2: Simplify 3cotA 1
Similarly, the expression 3cotA 1 represents 3 multiplied by the cotangent of angle A. Using the same logic as before, we can rewrite this as 3 * (cosA / sinA).

Step 3: Multiply the two expressions
Now that we have simplified both cotA 3 and 3cotA 1, we can multiply them together. Multiplying these two expressions involves multiplying the numerators and denominators separately.

(sinA * cosA * 3) / (sinA * sinA)

Step 4: Simplify the expression
To simplify further, we can cancel out the common factors in the numerator and denominator. In this case, sinA appears in both the numerator and denominator, so it can be canceled out.

(cosA * 3) / sinA

Therefore, the simplified expression of sinA(cotA 3)(3cotA 1) is (cosA * 3) / sinA.