Answer:
c. 108.4
Step-by-step explanation:
cos theta = (u dot v)/ (||u|| ||v||)
where dot stands for dot product and || || is the magnitude
u = (1,5) v= (7,-4)
u dot v = (1*7 + 5*-4) = 7-20 = -13
||u|| = sqrt( 1^2 +5^2) = sqrt(1+25) = sqrt(26)
||v|| = sqrt(7^2 + (-4)^2) = sqrt(49+16) = sqrt(65)
cos theta = -13/ sqrt(26) sqrt(65)
cos theta = -13 /sqrt(1690)
theta = arccos (-13/sqrt(1690))
theta = 108.43
25 x 16 = 400
400 x 15 = 6000
they raised $6000
hope this helps you
Answer:
The answer for the question is -1.5
We have the following equation:
x2 + y2 + 6y - 72 = 0
Rewriting we have:
x2 + y2 + 6y = 72
Complete squares we have:
x2 + y2 + 6y + (6/2) ^ 2 = 72 + (6/2) ^ 2
x2 + y2 + 6y + (3) ^ 2 = 72 + (3) ^ 2
x2 + y2 + 6y + 9 = 72 + 9
x2 + (y + 3) 2 = 81
So, the center is:
(0, -3)
The radio is:
r = 9
Answer:
(0, -3)
r = 9
Answer:
see explanation
Step-by-step explanation:
the sum to n terms of an arithmetic sequence is
= 
[2a + (n - 1)d ]
where d is the common difference and a is the first term
here d = 9 - 7 = 7 - 5 = 2 and a = 5, hence
= [(2 × 5) + 2(n - 1) ]
= (10 + 2n - 2)
= (2n + 8)
= n² + 4n
When sum = 165, then
n² + 4n = 165 ← rearrange into standard form
n² + 4n - 165 = 0 ← in standard form
(n + 15)(n - 11) = 0 ← in factored form
equate each factor to zero and solve for n
n + 15 = 0 ⇒ n = - 15
n - 11 = 0 ⇒ n = 11
but n > 0 ⇒ n = 11
