Answer:
D
Step-by-step explanation:
our basic Pythagorean identity is cos²(x) + sin²(x) = 1
we can derive the 2 other using the listed above.
1. (cos²(x) + sin²(x))/cos²(x) = 1/cos²(x)
1 + tan²(x) = sec²(x)
2.(cos²(x) + sin²(x))/sin²(x) = 1/sin²(x)
cot²(x) + 1 = csc²(x)
A. sin^2 theta -1= cos^2 theta
this is false
cos²(x) + sin²(x) = 1
isolating cos²(x)
cos²(x) = 1-sin²(x), not equal to sin²(x)-1
B. Sec^2 theta-tan^2 theta= -1
1 + tan²(x) = sec²(x)
sec²(x)-tan(x) = 1, not -1
false
C. -cos^2 theta-1= sin^2
cos²(x) + sin²(x) = 1
sin²(x) = 1-cos²(x), our 1 is positive not negative, so false
D. Cot^2 theta - csc^2 theta=-1
cot²(x) + 1 = csc²(x)
isolating 1
1 = csc²(x) - cot²(x)
multiplying both sides by -1
-1 = cot²(x) - csc²(x)
TRUE
The first one is 2x^2+2x-2
the second one is 2x^2-2x-2
the third one is 6h+6k
Answer:
B
Step-by-step explanation:
1) lets use elimination to solve this:
multiply 10x+4y=24 with 3 in order to get "4y" into "12y"
3(10x+4y=24)
30x+12y=72
now subtract both equations to eliminate 'y"
30x+12y=72
-
6x+12y=48
---------------------
24x=24
x=1
now substitute 1 in the above equation:
6(1)+12y=48
6+12y=48
12y=42
y=7/2
Answer:
125/2 or 62.5 or 62 1/2 (x=)
Step-by-step explanation:
25/4=x/10 multiply everything by 20
25*20/4=20x/10 simplify
25*5=2x simplify
125=2x divide on both sides
125/2 or 62.5 or 62 1/2=x
