Cosine Law:
c² = a² + b² - 2 a b cos C
Answer:
C ) area of square c² = area of square a² + area of square b²
- area of defect 1 - area of defect 2
Answer:
or 
Step-by-step explanation:
we know that
Applying the law of cosines

In this problem we have



substitute the values



Answer:
(2x-9)(2x+9)
Step-by-step explanation:
This is a difference of squares because it can be written as (2x)^2-9^2
The formula for factoring a difference of squares is a^2-b^2=(a-b)(a+b)
So replace a with 2x and b with 9 giving us
4x^2-81=(2x-9)(2x+9)