Answer:
first one with -1...21
Step-by-step explanation:
only one that follows quadratic formula format
<h2>
Ratio of area of the square to the area of the circle = π/4</h2>
Step-by-step explanation:
Let the side of square be a and radius of circle be r.
The perimeter of a particular square and the circumference of a particular circle are equal.
Perimeter of square = 4 x a = 4a
Circumference of circle = 2πr
Given that
4a = 2πr

We need to find the ratio of the area of the square to the area of the circle.
Area of the square = a²
Area of the circle = πr²

Ratio of area of the square to the area of the circle = π/4
D
using the double - angle identity
cos (2A) = cos² A - sin² A = 2cos² A - 1 = 1 - 2sin² A
the right side = 1 - 2sin² (112.5° ) with A = 22.5°
hence 2A = 2 × 22.5° = 45°
thus cos 45° = 1 - 2sin² ( 22.5°)
7(-3) is an example of multiplication. What the question wants you to do is multiply the outside number (7) by the inside number (-3).
Basically you are just multiplying -3 x 7.
Your product is -21