We have to break each degree in terms of 90
A) 
Which is in third quadrant, therefore sine is negative hence
B) 
Which is in third quadrant, therefore cosine is negative hence
C) 
Which is in third quadrant, therefore tangent is positive hence
D) 
Which is in third quadrant, therefore cosec is negative hence
not defined
E)
Which is in third quadrant, therefore secant is negative hence
F) 
Which is in third quadrant, therefore tangent is positive hence
not defined
Hence only 
and
have value -1
Hope this will help
54.4 Cups of soebet are used in 8 cups of punch.
Use subtitution method to solve the problem.
First, change y to the value of x in order to find the exact value of x.
x + y = 4
y = 4 - x
Second, subtitute y with 4 - x from the first equation
y = -x² + 2x + 4
4 - x = -x² + 2x + 4
move all terms to the left side
x² - 2x - x + 4 - 4 = 0
x² - 3x = 0
x(x - 3) = 0
x = 0 or x = 3
Third, now we have 2 values of x. Find the value of y for each of x
For x = 0
y = 4 - x
y = 4 - 0
y = 4
For x = 3
y = 4 - x
y = 4 - 3
y = 1
The solution is (0,4) and (3,1). The answer is option b
0.4 is four tenths. 0.4 = 4/10=2/5
Answer: the original cost of the item is 90$
Step-by-step explanation:
30% off of the item = 27$
27 dollar is 30% of the item
thus 27 = 0.30X
0.30X = 27
time both side by 10
3X = 270
270/3 = 90
