12-15=3 ............................................................

.... Hope this will help....
Hello :
cot(x) = cos(x)/sin(x) .... cot²(x) = cos²(x)/sin²(x)
1-sin²(x) = cos²(x)
cot²(x)(1-sin²(x)) = ( cos²(x)/sin²(x))× cos²(x) = 1/sin²(x)
Answer:
The answer is

Step-by-step explanation:
5x² + 9x + 2 = 0
Using the quadratic formula that's

From the question
a = 5 , b = 9 , c = 2
We have

We have the final answer as

Hope this helps you