Answer:

Step-by-step explanation:
Given

Required
Use the expression to prove a trigonometry identity
The given expression is not complete until it is written as:

Going by the Pythagoras theorem, we can assume the following.
- a = Opposite
- b = Adjacent
- r = Hypothenuse
So, we have:


Having said that:
The expression can be further simplified as:

Substitute values for sin and cos
becomes

Answer:
within-groups
Step-by-step explanation:
According to my research on the scientific method, I can say that based on the information provided within the question the independent variable is being manipulated within groups, because she is not using a pretest and her design is within-groups. This is because she is using the posttest-only control group design which is a research design where at least two groups, one of which does not receive a treatment or intervention, and data is collected on the outcome measure after the treatment or intervention.
I hope this answered your question. If you have any more questions feel free to ask away at Brainly.
Answer:
when x is any real number
Step-by-step explanation:
commutative property