Order of Operations:
PEMDAS
P: Parenthesis
E: Exponents
MD: Multiplication/Division
AS: Addition/Subtraction
Remember to do them in order.
E.G: 8(2+3)²-4/2
You do first the parenthesis(2+3), which is 6
Multiply 6 by 6(rule of exponents), which is 36.
Multiply 36 by 8, which is 288.
Divide 288 by 2, which is 144.
Subtract 144-2. It is 142.
Answer: 142
<u>Answer</u>
-3/√13
<u>Explanation</u>
We are going to take angle ∅ to be at the origin (point (0,0)).
The point at (-2, -3) means, 2 units to the left (negative side of x-axis) and 3 units downwards (negative side of y-xis).
This will make a right triangle with a hypotenuse of √(2²+3²) = √13
The angle ∅ is in the 3rd quadrant where cosine is negative.
cosine = adjacent/hypotenuse
The exact answer for cos ∅ = -2/√13