9514 1404 393
Answer:
obtuse
Step-by-step explanation:
The law of cosines tells you ...
b² = a² +c² -2ac·cos(B)
Substituting for a²+c² using the given equation, we have ...
b² = b²·cos(B)² -2ac·cos(B)
We can subtract b² to get a quadratic in standard form for cos(B).
b²·cos(B)² -2ac·cos(B) -b² = 0
Solving this using the quadratic formula gives ...
The fraction ac/b² is always positive, so the term on the right (the square root) is always greater than 1. The value of cos(B) cannot be greater than 1, so the only viable value for cos(B) is ...
The value of the radical is necessarily greater than ac/b², so cos(B) is necessarily negative. When cos(B) < 0, B > 90°. The triangle is obtuse.
Quadratic function ( in standard form ):
y = a x² + b x + c
x = 0:
635 = 0 + 0 + c
c = 635
x = 1:
644 = a + b + 635
a + b = 9
x = 2:
719 = 4 a + 2 b + 635
4 a + 2 b = 84
and now we have a system:
a + b = 9 / * ( - 2 )
4 a + 2 b = 84
-------------------------
- 2 a + 2 b = - 18
+
4 a + 2 b = 84
-------------------------
2 a = 66
a = 33; b = - 24;
Function is:
f ( x ) = 33 x² - 24 x + 635
f ( 8 ) = 33 * 64 - 24 * 8 + 635 = 2,112 - 192 + 635 = 2,555
Answer: The number of waterfowl on week 8 would be 2,555.
Let the amount deposited (principal) be x, then the amount after the required time = 2x.
A = P(1 + r/n)^nt: where A is the future value = 2x, P is the principal = x, r is the rate = 0.75%, n is the number of accumulation in a year = 12, t is the number of years.
2x = x(1 + 0.0075/12)^12t
2 = (1 + 0.000625)^12t
log 2 = 12t log (1.000625)
log 2 / log (1.000625) = 12t
1109.38 = 12t
t = 92 years
Answer:
l = 32.5 units, w= 27.5 units, A = 893.75 units²
Step-by-step explanation:
width is w
length is l = 5+w
P = 2( l+w) , substitute l for 5+w
P = 2(5+w+w)
P = 2(5+2w)
P = 10 +4w
P = 120
10 +4w = 120
4w = 120-10
4w = 110
w= 110/4
w= 27.5 units
l = 5+w = 5+ 27.5 = 32.5 units
A = l*w = 27.5 * 32.5 = 893.75 units ²
378% is the correct answer. Divide 280 by 100 to find 1 percent. Then multiply by 135 to find 135%
