A)
Using the unit circle, for the cos function to be positive, angle A must lie in either <u>quadrant I or quadrant IV</u>
B)
Using the unit circle, If the sine is negative, angle A must lie in either quadrant III or quadrant IV. Since we know that the cosine is positive, this only leaves <u>quadrant IV</u>
<u />
D)
cos = adj/hyp
Using Pythagorean theorem,

b = ±5 (we know its -5 since we know sinA is negative)
this means that the x coord is 12, and the y coord is -5
any proportion of these two numbers would work as an answer
e.g. <u>(12, -5), (24,-10), (12/13, -5/13),</u> are all valid answers
E)
sinA = opp/hyp
<u>sinA = -5/13</u>
tanA = opp/adj
<u>tanA = -5/12</u>
Answer:The last answer doesn't have a solution of -2
Step-by-step explanation:
Step-by-step explanation:
ax^2+bx+c=0
a=leading term
ok so if the leading term is positive then opens up and has a <u>min</u>
if leading term is negative then opens down and has a <u>max</u>
leading term is positive
1x^2+8x
it has a min
to complete the square, move c aside take 1/2 of b and square it
b=8
8/2=4
4^2=16
now add that to both sides
x^2+8x+16+6=0+16
factor perfect square
(x+4)^2+6=16
subtract 6
(x+4)^2=10
subtract 10
(x+4)^2-10=0
vertex aka min or max is (h,k) when ou have
y=a(x-h)+k
h=-4
k=-10
5x^2 + 7
the coefficient is 5
the variable is x
the exponent is 2
the constant is 7
False because a number is rational if we can write it as a fraction where the top number of and bottom number are both whole numbers but irrational numbers is any number that is not rational. It is a number that cannot be written as a ratio of two integers(or cannot be expressed as a fraction)