Answer:
sin θ = 15/17
Step-by-step explanation:
First we have to know how much the hypotenuse measures.
to take out the hypotenuse we will use pitagoras, with the following formula.
h^2 = c1^2 + c2^2
c1 = 8
c2 = 15
h^2 = 8^2 + 15^2
h^2 = 64 + 225
h = √ 289
h = 17
well to start we have to know the relationships between angles, legs and the hypotenuse.
a: adjacent
o: opposite
h: hypotenuse
sin θ = o/h
cos θ= a/h
tan θ = o/a
we want to know the sin of θ
sin θ = o/h
sin θ = 15/17
Answer:
a) For this case we can use the fact that 
And for this case since we ar einterested on
and we know that the if we are below the y axis the sine would be negative then:

b) From definition we can use the fact that
and we got this:

We can use the notabl angle
and we know that :

Then we know that
correspond to 225 degrees and that correspond to the III quadrant, and we know that the sine and cosine are negative on this quadrant. So then we have this:

Step-by-step explanation:
For this case we can use the notable angls given on the picture attached.
Part a
For this case we can use the fact that 
And for this case since we ar einterested on
and we know that the if we are below the y axis the sine would be negative then:

Part b
From definition we can use the fact that
and we got this:

We can use the notabl angle
and we know that :

Then we know that
correspond to 225 degrees and that correspond to the III quadrant, and we know that the sine and cosine are negative on this quadrant. So then we have this:

Answer:
2x+5
Step-by-step explanation:
X represents the number in "2 times a number." You could insert any number into x.