Cos⁴A - cos²A = sin⁴A - sin²A

Answer- cos(2A) - 1

*** I'm not very sure of the answer. Because I'm not very good at math.

How to make-

cos⁴A - cos²A = sin⁴A - sin²A

= cos(A)⁴ -1 - sin(A)⁴

= (cos(A)² - sin(A)²) × (cos (A)² + sin(A)²) -1

= cos (2A) × (cos(A)² + sin(A)²) -1

= cos(2A) × 1 - 1

= cos(2A) - 1

Step-by-step explanation:

x * 450 = 18.5                     This means that 450 * a % = 18.50. Divide by 450

x * 450/450 = 18.5/450

x = 0.041111

Multiply by 100 to get a percent.

0. 0411 * 100 = 4.11 %