Answer:
It is an identity, the proof is in the explanation
Step-by-step explanation:
csc(A)-cot(A)=tan(A/2)
I'm going to start with right hand side
tan(A/2)=(1-cos(a))/(sin(a)) half angle identity
tan(A/2)=1/sin(a)-cos(a)/sin(a) separate fraction
tan(A/2)=csc(a)-cot(a) reciprocal and quotient identities
For the equation to work, you have to have the same number on both sides of the equal sign
so to find ?, you can do:
13 - 2 = 12 - ? Simplify
11 = 12 - ? Subtract 12 on both sides
-1 = - ? Multiply -1 on both sides
1 = ?
A system is inconsistent when there are no solutions between the two equations. Graphically, the lines will be parallel (they never meet!) and the slopes will be the same. But the y-intercepts will be different.
Let's look at the four equations, with each solved as needed, into y = mx + b form.
A: 2x + y = 5
y = 5 - 2x
y = -2x + 5
Compared to y = 2x + 5, the slopes are different, so this system won't be inconsistent. Not a good choice.
B: y = 2x + 5
Compared to y = 2x + 5, the slopes are the same and the y intercepts are the same. This system has infinitely many solutions. Not a good choice.
C: 2x - 4y = 10
-4y = 10 - 2x
-4y = -2x + 10
y = 2/4x -10/4
Here the slopes are different, so, like A this is not a good choice.
D: 2y - 4x = -10
2y = =10 + 4x
2y = 4x - 10
y = 2x - 5
Compared to y = 2x + 5 we have the same slopes and different y intercepts. The lines will be parallel and the system is inconsistent.
Thus, D is the best choice.
Answer:
$1.30
Step-by-step explanation:
What you do is add the original 65 cents to the additional 65 cents that were shown to get 130. Since it's more than 100 you make it into dollars, so the final answer is $1.30.
