Answer:
the law of cosines with ABC
Answer:
3
Step-by-step explanation:
Slope = y2- y1/ x2- x1
= 4 - (-2) / 3 -1
= 4+2/ 2
=6/2 = 3
35 + 52 + 3(x + 2) = 180
87 + 3x + 6 = 180 ( add the like terms and use distributive property)
93 + 3x = 180
-93 -93
3x = 87
÷3 ÷3
x = 29
( the sum of all triangle angles is 180)
Answer:
C. 
Step-by-step explanation:
Given the two equations:

To find:
The correct option when value of y is substituted to 2nd equation using the 1st equation.
Solution:
First of all, let us learn about the substitution method.
Substitution method is the method to provide solutions to two variables when we have two equations and two variables.
In substitution method, we find the value of one variable in terms of the other variable and put this value in the other equation.
Now, the other equation becomes only single variable and then we solve for the variable's value.
Here, we have two equations and value of one varible is:

Let us put value of y in 2nd equation:

So, the correct answer is option C. 
Answer:
Step-by-step explanation:
The idea here is to get the left side simplified down so it is the same as the right side. Consequently, there are 3 identities for cos(2x):
,
, and

We begin by rewriting the left side in terms of sin and cos, since all the identities deal with sines and cosines and no cotangents or cosecants. Rewriting gives you:

Notice I also wrote the 1 in terms of sin^2(x).
Now we will put the numerator of the bigger fraction over the common denominator:

The rule is bring up the lower fraction and flip it to multiply, so that will give us:

And canceling out the sin^2 x leaves us with just
which is one of our identities.