Question:

Answer:


Step-by-step explanation:
Given

Required
Simplify
In trigonometry:

So, the expression becomes:

Simplify the denominator




Express the fraction as:





Rationalize



In trigonometry:

Hence:


All of them are true.
A: Rule.
B: There exist such functions f and g that satisfy the equality.
C: According to (A) this is acceptable.
D: Rule.
Hope this helps.
The answer to this question is:
y = -2x - 1
Answer:

Step-by-step explanation:
Cosine (cos) is adjacent by hypotenuse. 
In any of the 45° angles, 1 is adjacent and √2 is the hypotenuse.
So arrange them to get 