For this case we have:
By trigonometric property we have:

Where:

Substituting:

Clearing x we have:

Thus, the equation is: 
Answer:

algebra, is a type of math.
I think you count the squares in the middle or radius ?
I don't know what you have to do but I'm trying to do my first answer srry
Answer:
1/5 chance
cause there are 5 people in the family and there is 1 brother and 1 spot for the front of the line
Step-by-step explanation: