Answer:
This study uses random sampling
This study uses a control group
This study uses a repeated measures design
Use the chain rule.
Let u = 25sin²(x), such that dy/dx = dy/du · du/dx


Answer:
The factored form of x²-400 is (x+20)(x-20).
Step-by-step explanation:
Given the expression

As the square of 20 is 400. Therefore, rewrite 400 as 20²
⇒ 

Thus, the expression becomes

Thus, the factored form of x²-400 is (x+20)(x-20).