Answer:
It returns the angle whose cosine is a given number.
Step-by-step explanation:
For every trigonometry function, there is an inverse function that works in reverse. These inverse functions have the same name but with 'arc' in front. (On some calculators the arccos button may be labeled arccos, or sometimes cos-1.) So the inverse of cos is arccos etc. When we see "arccos x", we understand it as "the angle whose cosine is x"
cos30 = 0.866 Means: The cosine of 30 degrees is 0.866
arccos 0.866 = 30 Means: The angle whose cosine is 0.866 is 30 degrees.
Use arccos when you know the cosine of an angle and want to know the actual angle.
Answer:
y would be 90 degrees
Step-by-step explanation:
The triangle has a right angle which is where y is located. A right angle is usually 90 degrees.
Answer:
D. 29
Step-by-step explanation:
When you plug -2 into the equation, you get 4(4) - 3(-2) +7, which is equal to 16+6+7 = 29
7.
1) Given (info from top)
2) <BCA =~ <DCE (vertical angles theorem)
3) triangle BCA =~ triangle DCE (SAS)
4) BA =~ ED (CPCTC)
=~ means congruent
8.
1) Given
2) CA =~ AC (reflexive property of equality)
3) triangle ACB =~ triangle ACD (ASA)
4) BC =~ CD (CPCTC)
Hope this helps!! :)