According to the trigonometric functions, we can see that angle x can be found through the one that involves the adjacent side and the hypotenuse, which in this case is the cos,

then, if we apply the inverse we can find the value of x,

Answer:
For number 9 the answer is B
Since segment AC bisects (aka cuts in half) angle A, this means the two angles CAB and CAD are the same measure. I'll refer to this later as "fact 1".
Triangles ABC and ADC have the shared segment AC between them. By the reflexive property AC = AC. Any segment is equal in length to itself. I'll call this "fact 2" later on.
Similar to fact 1, we have angle ACB = angle ACD. This is because AC bisects angle BCD into two smaller equal halves. I'll call this fact 3
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To summarize so far, we have these three facts
- angle CAB = angle CAD
- AC = AC
- angle ACB = angle ACD
in this exact order, we can use the ASA (angle side angle) congruence property to prove the two triangles are congruent. Facts 1 and 3 refer to the "A" parts of "ASA", while fact 2 refers to the "S" of "ASA". The order matters. Notice how the side is between the angles in question.
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Once we prove the triangles are congruent, we use CPCTC (corresponding parts of congruent triangles are congruent) to conclude that AB = AD and BC = BD. These pair of sides correspond, so they must be congruent in order for the entire triangles to be congruent overall.
It's like saying you had 2 identical houses, so the front doors must be the same. The houses are the triangles (the larger structure) and the door is an analogy to the sides (which are pieces of the larger structure).
Answer:
See below
Step-by-step explanation:
13x + 5 + 17x - 4.5 + x
NOTE: You can only add/subtract LIKE terms . Here we have variable terms in x (13x , 17x and x) and 2 constants ( 5 and 4.5).
Sarah's next line is
18x + 17x - 4.5 + x
This is incorrect . It looks like she added 13x + 5 and got 18x!! Which is of course wrong because they are NOT LIKE terms. 5 is a constant and 13x is a variable term in x.
The third line is correct:-
35x - 4.5 + x.
She has added the 2 variables 17x and 18x.
Fourth line is 30.5x + x. She's at it again - Trying to subtract 4.5 from 35x .
Last line 31.5x
She has added the 2 terms in x correctly, but the final answer is wrong of course due to the earlier errors.